Apollo Server is an open-source, spec-compliant GraphQL server that's compatible with any GraphQL client, including Apollo Client. In versions from 2.0.0 to 3.13.0, 4.2.0 to before 4.13.0, and 5.0.0 to before 5.4.0, the default configuration of startStandaloneServer from @apollo/server/standalone is vulnerable to denial of service (DoS) attacks through specially crafted request bodies with exotic character set encodings. This issue does not affect users that use @apollo/server as a dependency for integration packages, like @as-integrations/express5 or @as-integrations/next, only direct usage of startStandaloneServer.

The Apollo Router Core is a configurable, high-performance graph router written in Rust to run a federated supergraph that uses Apollo Federation 2. Instances of the Apollo Router running versions >=1.21.0 and < 1.52.1 are impacted by a denial of service vulnerability if _all_ of the following are true: 1. The Apollo Router has been configured to support [External Coprocessing](https://www.apollographql.com/docs/router/customizations/coprocessor). 2. The Apollo Router has been configured to send request bodies to coprocessors. This is a non-default configuration and must be configured intentionally by administrators. Instances of the Apollo Router running versions >=1.7.0 and <1.52.1 are impacted by a denial-of-service vulnerability if all of the following are true: 1. Router has been configured to use a custom-developed Native Rust Plugin. 2. The plugin accesses Request.router_request in the RouterService layer. 3. You are accumulating the body from Request.router_request into memory. If using an impacted configuration, the Router will load entire HTTP request bodies into memory without respect to other HTTP request size-limiting configurations like limits.http_max_request_bytes. This can cause the Router to be out-of-memory (OOM) terminated if a sufficiently large request is sent to the Router. By default, the Router sets limits.http_max_request_bytes to 2 MB. If you have an impacted configuration as defined above, please upgrade to at least Apollo Router 1.52.1. If you cannot upgrade, you can mitigate the denial-of-service opportunity impacting External Coprocessors by setting the coprocessor.router.request.body configuration option to false. Please note that changing this configuration option will change the information sent to any coprocessors you have configured and may impact functionality implemented by those coprocessors. If you have developed a Native Rust Plugin and cannot upgrade, you can update your plugin to either not accumulate the request body or enforce a maximum body size limit. You can also mitigate this issue by limiting HTTP body payload sizes prior to the Router (e.g., in a proxy or web application firewall appliance).

Apollo Federation is an architecture for declaratively composing APIs into a unified graph. Each team can own their slice of the graph independently, empowering them to deliver autonomously and incrementally. Instances of @apollo/query-planner >=2.0.0 and <2.8.5 are impacted by a denial-of-service vulnerability. @apollo/gateway versions >=2.0.0 and < 2.8.5 and Apollo Router <1.52.1 are also impacted through their use of @apollo/query-panner. If @apollo/query-planner is asked to plan a sufficiently complex query, it may loop infinitely and never complete. This results in unbounded memory consumption and either a crash or out-of-memory (OOM) termination. This issue can be triggered if you have at least one non-@key field that can be resolved by multiple subgraphs. To identify these shared fields, the schema for each subgraph must be reviewed. The mechanism to identify shared fields varies based on the version of Federation your subgraphs are using. You can check if your subgraphs are using Federation 1 or Federation 2 by reviewing their schemas. Federation 2 subgraph schemas will contain a @link directive referencing the version of Federation being used while Federation 1 subgraphs will not. For example, in a Federation 2 subgraph, you will find a line like @link(url: "https://specs.apollo.dev/federation/v2.0"). If a similar @link directive is not present in your subgraph schema, it is using Federation 1. Note that a supergraph can contain a mix of Federation 1 and Federation 2 subgraphs. This issue results from the Apollo query planner attempting to use a Number exceeding Javascript’s Number.MAX_VALUE in some cases. In Javascript, Number.MAX_VALUE is (2^1024 - 2^971). When the query planner receives an inbound graphql request, it breaks the query into pieces and for each piece, generates a list of potential execution steps to solve the piece. These candidates represent the steps that the query planner will take to satisfy the pieces of the larger query. As part of normal operations, the query planner requires and calculates the number of possible query plans for the total query. That is, it needs the product of the number of query plan candidates for each piece of the query. Under normal circumstances, after generating all query plan candidates and calculating the number of all permutations, the query planner moves on to stack rank candidates and prune less-than-optimal options. In particularly complex queries, especially those where fields can be solved through multiple subgraphs, this can cause the number of all query plan permutations to balloon. In worst-case scenarios, this can end up being a number larger than Number.MAX_VALUE. In Javascript, if Number.MAX_VALUE is exceeded, Javascript represents the value as “infinity”. If the count of candidates is evaluated as infinity, the component of the query planner responsible for pruning less-than-optimal query plans does not actually prune candidates, causing the query planner to evaluate many orders of magnitude more query plan candidates than necessary. This issue has been addressed in @apollo/query-planner v2.8.5, @apollo/gateway v2.8.5, and Apollo Router v1.52.1. Users are advised to upgrade. This issue can be avoided by ensuring there are no fields resolvable from multiple subgraphs. If all subgraphs are using Federation 2, you can confirm that you are not impacted by ensuring that none of your subgraph schemas use the @shareable directive. If you are using Federation 1 subgraphs, you will need to validate that there are no fields resolvable by multiple subgraphs.

The Apollo Router Core is a configurable, high-performance graph router written in Rust to run a federated supergraph that uses Apollo Federation 2. A vulnerability in Apollo Router's usage of Apollo Compiler allowed queries with deeply nested and reused named fragments to be prohibitively expensive to validate. This could lead to excessive resource consumption and denial of service. Apollo Router's usage of Apollo Compiler has been updated so that validation logic processes each named fragment only once, preventing redundant traversal. This has been remediated in apollo-router versions 1.61.2 and 2.1.1.

Apollo Gateway provides utilities for combining multiple GraphQL microservices into a single GraphQL endpoint. Prior to 2.10.1, a vulnerability in Apollo Gateway allowed queries with deeply nested and reused named fragments to be prohibitively expensive to query plan, specifically during named fragment expansion. Named fragments were being expanded once per fragment spread during query planning, leading to exponential resource usage when deeply nested and reused fragments were involved. This could lead to excessive resource consumption and denial of service. This has been remediated in @apollo/gateway version 2.10.1.

The Apollo Router Core is a configurable, high-performance graph router written in Rust to run a federated supergraph that uses Apollo Federation 2. A vulnerability in Apollo Router allowed queries with deeply nested and reused named fragments to be prohibitively expensive to query plan, specifically due to internal optimizations being frequently bypassed. The query planner includes an optimization that significantly speeds up planning for applicable GraphQL selections. However, queries with deeply nested and reused named fragments can generate many selections where this optimization does not apply, leading to significantly longer planning times. Because the query planner does not enforce a timeout, a small number of such queries can exhaust router's thread pool, rendering it inoperable. This could lead to excessive resource consumption and denial of service. This has been remediated in apollo-router versions 1.61.2 and 2.1.1.

apollo-compiler is a query-based compiler for the GraphQL query language. Prior to 1.27.0, a vulnerability in Apollo Compiler allowed queries with deeply nested and reused named fragments to be prohibitively expensive to validate. Named fragments were being processed once per fragment spread in some cases during query validation, leading to exponential resource usage when deeply nested and reused fragments were involved. This could lead to excessive resource consumption and denial of service in applications. This vulnerability is fixed in 1.27.0.

Apollo Gateway provides utilities for combining multiple GraphQL microservices into a single GraphQL endpoint. Prior to 2.10.1, a vulnerability in Apollo Gateway allowed queries with deeply nested and reused named fragments to be prohibitively expensive to query plan, specifically due to internal optimizations being frequently bypassed. The query planner includes an optimization that significantly speeds up planning for applicable GraphQL selections. However, queries with deeply nested and reused named fragments can generate many selections where this optimization does not apply, leading to significantly longer planning times. Because the query planner does not enforce a timeout, a small number of such queries can render gateway inoperable. This could lead to excessive resource consumption and denial of service. This has been remediated in @apollo/gateway version 2.10.1.

The Apollo Router Core is a configurable, high-performance graph router written in Rust to run a federated supergraph that uses Apollo Federation 2. Prior to 1.61.2 and 2.1.1, a vulnerability in Apollo Router allowed queries with deeply nested and reused named fragments to be prohibitively expensive to query plan, specifically during named fragment expansion. Named fragments were being expanded once per fragment spread during query planning, leading to exponential resource usage when deeply nested and reused fragments were involved. This could lead to excessive resource consumption and denial of service. This has been remediated in apollo-router versions 1.61.2 and 2.1.1.

The Apollo Router Core is a configurable, high-performance graph router written in Rust to run a federated supergraph that uses Apollo Federation 2. Prior to 1.61.2 and 2.1.1, the operation limits plugin uses unsigned 32-bit integers to track limit counters (e.g. for a query's height). If a counter exceeded the maximum value for this data type (4,294,967,295), it wrapped around to 0, unintentionally allowing queries to bypass configured thresholds. This could occur for large queries if the payload limit were sufficiently increased, but could also occur for small queries with deeply nested and reused named fragments. This has been remediated in apollo-router versions 1.61.2 and 2.1.1.

The Apollo Router is a configurable, high-performance graph router written in Rust to run a federated supergraph that uses Apollo Federation. Affected versions are subject to a Denial-of-Service (DoS) type vulnerability which causes the Router to panic and terminate when a multi-part response is sent. When users send queries to the router that uses the `@defer` or Subscriptions, the Router will panic. To be vulnerable, users of Router must have a coprocessor with `coprocessor.supergraph.response` configured in their `router.yaml` and also to support either `@defer` or Subscriptions. Apollo Router version 1.33.0 has a fix for this vulnerability which was introduced in PR #4014. Users are advised to upgrade. Users unable to upgrade should avoid using the coprocessor supergraph response or disable defer and subscriptions support and continue to use the coprocessor supergraph response.

The Apollo Router is a configurable, high-performance graph router written in Rust to run a federated supergraph that uses Apollo Federation 2. Affected versions are subject to a Denial-of-Service (DoS) type vulnerability which causes the Router to panic and terminate when GraphQL Subscriptions are enabled. It can be triggered when **all of the following conditions are met**: 1. Running Apollo Router v1.28.0, v1.28.1 or v1.29.0 ("impacted versions"); **and** 2. The Supergraph schema provided to the Router (either via Apollo Uplink or explicitly via other configuration) **has a `subscription` type** with root-fields defined; **and** 3. The YAML configuration provided to the Router **has subscriptions enabled** (they are _disabled_ by default), either by setting `enabled: true` _or_ by setting a valid `mode` within the `subscriptions` object (as seen in [subscriptions' documentation](https://www.apollographql.com/docs/router/executing-operations/subscription-support/#router-setup)); **and** 4. An [anonymous](https://spec.graphql.org/draft/#sec-Anonymous-Operation-Definitions) (i.e., un-named) `subscription` operation (e.g., `subscription { ... }`) is received by the Router If **all four** of these criteria are met, the impacted versions will panic and terminate. There is no data-privacy risk or sensitive-information exposure aspect to this vulnerability. This is fixed in Apollo Router v1.29.1. Users are advised to upgrade. Updating to v1.29.1 should be a clear and simple upgrade path for those running impacted versions. However, if Subscriptions are **not** necessary for your Graph – but are enabled via configuration — then disabling subscriptions is another option to mitigate the risk.

In h2oai/h2o-3 version 3.46.0.2, a vulnerability exists where uploading and repeatedly parsing a large GZIP file can cause a denial of service. The server becomes unresponsive due to memory exhaustion and a large number of concurrent slow-running jobs. This issue arises from the improper handling of highly compressed data, leading to significant data amplification.

.NET and Visual Studio Denial of Service Vulnerability

GuardDog is a CLI tool to identify malicious PyPI packages. Prior to 2.7.1, GuardDog's safe_extract() function does not validate decompressed file sizes when extracting ZIP archives (wheels, eggs), allowing attackers to cause denial of service through zip bombs. A malicious package can consume gigabytes of disk space from a few megabytes of compressed data. This vulnerability is fixed in 2.7.1.

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.30.1, a Denial of Service (DoS) vulnerability exists in cpp-httplib due to the unsafe handling of compressed HTTP request bodies (Content-Encoding: gzip, br, etc.). The library validates the payload_max_length against the compressed data size received from the network, but does not limit the size of the decompressed data stored in memory.

urllib3 is an HTTP client library for Python. urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading the content in chunks, rather than loading the entire response body into memory at once. urllib3 can perform decoding or decompression based on the HTTP `Content-Encoding` header (e.g., `gzip`, `deflate`, `br`, or `zstd`). When using the streaming API, the library decompresses only the necessary bytes, enabling partial content consumption. Starting in version 1.22 and prior to version 2.6.3, for HTTP redirect responses, the library would read the entire response body to drain the connection and decompress the content unnecessarily. This decompression occurred even before any read methods were called, and configured read limits did not restrict the amount of decompressed data. As a result, there was no safeguard against decompression bombs. A malicious server could exploit this to trigger excessive resource consumption on the client. Applications and libraries are affected when they stream content from untrusted sources by setting `preload_content=False` when they do not disable redirects. Users should upgrade to at least urllib3 v2.6.3, in which the library does not decode content of redirect responses when `preload_content=False`. If upgrading is not immediately possible, disable redirects by setting `redirect=False` for requests to untrusted source.

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Versions 3.13.2 and below allow a zip bomb to be used to execute a DoS against the AIOHTTP server. An attacker may be able to send a compressed request that when decompressed by AIOHTTP could exhaust the host's memory. This issue is fixed in version 3.13.3.

Envoy is a cloud-native high-performance proxy. In versions prior to 1.22.1 secompressors accumulate decompressed data into an intermediate buffer before overwriting the body in the decode/encodeBody. This may allow an attacker to zip bomb the decompressor by sending a small highly compressed payload. Maliciously constructed zip files may exhaust system memory and cause a denial of service. Users are advised to upgrade. Users unable to upgrade may consider disabling decompression.

Turms AI-Serving module v0.10.0-SNAPSHOT and earlier contains an image decompression bomb denial of service vulnerability. The ExtendedOpenCVImage class in ai/djl/opencv/ExtendedOpenCVImage.java loads images using OpenCV's imread() function without validating dimensions or pixel count before decompression. An attacker can upload a specially crafted compressed image file (e.g., PNG) that is small when compressed but expands to gigabytes of memory when loaded. This causes immediate memory exhaustion, OutOfMemoryError, and service crash. No authentication is required if the OCR service is publicly accessible. Multiple requests can completely deny service availability.

urllib3 is a user-friendly HTTP client library for Python. Starting in version 1.0 and prior to 2.6.0, the Streaming API improperly handles highly compressed data. urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading the content in chunks, rather than loading the entire response body into memory at once. When streaming a compressed response, urllib3 can perform decoding or decompression based on the HTTP Content-Encoding header (e.g., gzip, deflate, br, or zstd). The library must read compressed data from the network and decompress it until the requested chunk size is met. Any resulting decompressed data that exceeds the requested amount is held in an internal buffer for the next read operation. The decompression logic could cause urllib3 to fully decode a small amount of highly compressed data in a single operation. This can result in excessive resource consumption (high CPU usage and massive memory allocation for the decompressed data.

pypdf is a free and open-source pure-python PDF library. Prior to version 6.1.3, an attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing the content stream of a page using the LZWDecode filter. This has been fixed in pypdf version 6.1.3.

Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In netty-codec-compression versions 4.1.124.Final and below, and netty-codec versions 4.2.4.Final and below, when supplied with specially crafted input, BrotliDecoder and certain other decompression decoders will allocate a large number of reachable byte buffers, which can lead to denial of service. BrotliDecoder.decompress has no limit in how often it calls pull, decompressing data 64K bytes at a time. The buffers are saved in the output list, and remain reachable until OOM is hit. This is fixed in versions 4.1.125.Final of netty-codec and 4.2.5.Final of netty-codec-compression.

kin-openapi is a Go project for handling OpenAPI files. Prior to 0.131.0, when validating a request with a multipart/form-data schema, if the OpenAPI schema allows it, an attacker can upload a crafted ZIP file (e.g., a ZIP bomb), causing the server to consume all available system memory. The root cause comes from the ZipFileBodyDecoder, which is registered automatically by the module (contrary to what the documentation says). This vulnerability is fixed in 0.131.0.