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Vulnerability Details :

CVE-2026-27807

Summary
Assigner-GitHub_M
Assigner Org ID-a0819718-46f1-4df5-94e2-005712e83aaa
Published At-06 Mar, 2026 | 02:48
Updated At-06 Mar, 2026 | 16:10
Rejected At-
Credits

MarkUs: YAML alias (‘billion laughs’) DoS in config upload

MarkUs is a web application for the submission and grading of student assignments. Prior to version 2.9.4, MarkUs allows course instructors to upload YAML files to create/update various entities (e.g., assignment settings). These YAML files are parsed with aliases enabled. This issue has been patched in version 2.9.4.

Vendors
-
Not available
Products
-
Metrics (CVSS)
VersionBase scoreBase severityVector
Weaknesses
Attack Patterns
Solution/Workaround
References
HyperlinkResource Type
EPSS History
Score
Latest Score
-
N/A
No data available for selected date range
Percentile
Latest Percentile
-
N/A
No data available for selected date range
Stakeholder-Specific Vulnerability Categorization (SSVC)
▼Common Vulnerabilities and Exposures (CVE)
cve.org
Assigner:GitHub_M
Assigner Org ID:a0819718-46f1-4df5-94e2-005712e83aaa
Published At:06 Mar, 2026 | 02:48
Updated At:06 Mar, 2026 | 16:10
Rejected At:
▼CVE Numbering Authority (CNA)
MarkUs: YAML alias (‘billion laughs’) DoS in config upload

MarkUs is a web application for the submission and grading of student assignments. Prior to version 2.9.4, MarkUs allows course instructors to upload YAML files to create/update various entities (e.g., assignment settings). These YAML files are parsed with aliases enabled. This issue has been patched in version 2.9.4.

Affected Products
Vendor
MarkUsProject
Product
Markus
Versions
Affected
  • < 2.9.4
Problem Types
TypeCWE IDDescription
CWECWE-776CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
Type: CWE
CWE ID: CWE-776
Description: CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
Metrics
VersionBase scoreBase severityVector
3.14.9MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Version: 3.1
Base score: 4.9
Base severity: MEDIUM
Vector:
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions
Configurations
Workarounds
Exploits
Credits
Timeline
EventDate
Replaced By
Rejected Reason
References
HyperlinkResource
https://github.com/MarkUsProject/Markus/security/advisories/GHSA-m9rx-85mx-q9h6
x_refsource_CONFIRM
https://github.com/MarkUsProject/Markus/releases/tag/v2.9.4
x_refsource_MISC
Hyperlink: https://github.com/MarkUsProject/Markus/security/advisories/GHSA-m9rx-85mx-q9h6
Resource:
x_refsource_CONFIRM
Hyperlink: https://github.com/MarkUsProject/Markus/releases/tag/v2.9.4
Resource:
x_refsource_MISC
▼Authorized Data Publishers (ADP)
CISA ADP Vulnrichment
Affected Products
Metrics
VersionBase scoreBase severityVector
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions
Configurations
Workarounds
Exploits
Credits
Timeline
EventDate
Replaced By
Rejected Reason
References
HyperlinkResource
Information is not available yet
▼National Vulnerability Database (NVD)
nvd.nist.gov
Source:security-advisories@github.com
Published At:06 Mar, 2026 | 04:16
Updated At:12 Mar, 2026 | 17:22

MarkUs is a web application for the submission and grading of student assignments. Prior to version 2.9.4, MarkUs allows course instructors to upload YAML files to create/update various entities (e.g., assignment settings). These YAML files are parsed with aliases enabled. This issue has been patched in version 2.9.4.

CISA Catalog
Date AddedDue DateVulnerability NameRequired Action
N/A
Date Added: N/A
Due Date: N/A
Vulnerability Name: N/A
Required Action: N/A
Metrics
TypeVersionBase scoreBase severityVector
Secondary3.14.9MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Type: Secondary
Version: 3.1
Base score: 4.9
Base severity: MEDIUM
Vector:
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
CPE Matches
markusproject
markusproject
>>markus>>Versions before 2.9.4(exclusive)
cpe:2.3:a:markusproject:markus:*:*:*:*:*:*:*:*
Weaknesses
CWE IDTypeSource
CWE-776Primarysecurity-advisories@github.com
CWE ID: CWE-776
Type: Primary
Source: security-advisories@github.com
Evaluator Description
Evaluator Impact

Evaluator Solution

Vendor Statements
References
HyperlinkSourceResource
https://github.com/MarkUsProject/Markus/releases/tag/v2.9.4security-advisories@github.com
Product
Release Notes
https://github.com/MarkUsProject/Markus/security/advisories/GHSA-m9rx-85mx-q9h6security-advisories@github.com
Vendor Advisory
Hyperlink: https://github.com/MarkUsProject/Markus/releases/tag/v2.9.4
Source: security-advisories@github.com
Resource:
Product
Release Notes
Hyperlink: https://github.com/MarkUsProject/Markus/security/advisories/GHSA-m9rx-85mx-q9h6
Source: security-advisories@github.com
Resource:
Vendor Advisory

Change History

0
Information is not available yet

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2Records found
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Matching Score-4
Assigner-Ivanti
ShareView Details
Matching Score-4
Assigner-Ivanti
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EPSS-1.04% / 77.62%
||
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Published-12 Aug, 2025 | 15:00
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XEE in Ivanti Connect Secure before 22.7R2.8 or 22.8R2, Ivanti Policy Secure before 22.7R1.5, Ivanti ZTA Gateway before 22.8R2.3-723 and Ivanti Neurons for Secure Access before 22.8R1.4 (Fix deployed on 02-Aug-2025) allows a remote authenticated attacker with admin privileges to trigger a denial of service

Action-Not Available
Vendor-Ivanti Software
Product-connect_securepolicy_secureneurons_for_secure_accesszero_trust_access_gatewayConnect SecurePolicy SecureZTA GatewayNeurons for Secure Access
CWE ID-CWE-776
Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
CVE-2023-3569
Matching Score-4
Assigner-CERT@VDE
ShareView Details
Matching Score-4
Assigner-CERT@VDE
CVSS Score-4.9||MEDIUM
EPSS-0.27% / 50.58%
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7 Day CHG~0.00%
Published-08 Aug, 2023 | 06:56
Updated-27 Feb, 2025 | 21:10
Rejected-Not Available
Known To Be Used In Ransomware Campaigns?-Not Available
KEV Added-Not Available
KEV Action Due Date-Not Available
PHOENIX CONTACT: Denial-of-Service due to malicious XML files in TC ROUTER, TC CLOUD CLIENT and CLOUD CLIENT

In PHOENIX CONTACTs TC ROUTER and TC CLOUD CLIENT in versions prior to 2.07.2 as well as CLOUD CLIENT 1101T-TX/TX prior to 2.06.10 an authenticated remote attacker with admin privileges could upload a crafted XML file which causes a denial-of-service.

Action-Not Available
Vendor-Phoenix Contact GmbH & Co. KG
Product-tc_router_3002t-4g_vzw_firmwaretc_router_3002t-4gtc_router_3002t-4g_vzwcloud_client_1101t-txtc_cloud_client_1002-4g_firmwaretc_cloud_client_1002-4g_att_firmwaretc_cloud_client_1002-4g_vzwtc_router_3002t-4g_atttc_cloud_client_1002-4g_attcloud_client_1101t-tx_firmwaretc_router_3002t-4g_firmwaretc_cloud_client_1002-4gtc_router_3002t-4g_att_firmwaretc_cloud_client_1002-4g_vzw_firmwareTC ROUTER 3002T-4G ATTTC ROUTER 3002T-4GCLOUD CLIENT 1101T-TX/TXTC CLOUD CLIENT 1002-4GTC CLOUD CLIENT 1002-4G VZWTC CLOUD CLIENT 1002-4G ATTTC ROUTER 3002T-4G VZW
CWE ID-CWE-776
Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
Details not found