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Vulnerability Details :

CVE-2026-40687

Summary
Assigner-mitre
Assigner Org ID-8254265b-2729-46b6-b9e3-3dfca2d5bfca
Published At-30 Apr, 2026 | 00:00
Updated At-01 May, 2026 | 14:25
Rejected At-
Credits

In Exim before 4.99.2, when the SPA authentication driver is used with an adversarial SPA resource, there can be an out-of-bounds write that crashes the connection instance, or erroneous data processing that divulges data from uninitialized heap memory.

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:mitre
Assigner Org ID:8254265b-2729-46b6-b9e3-3dfca2d5bfca
Published At:30 Apr, 2026 | 00:00
Updated At:01 May, 2026 | 14:25
Rejected At:
▼CVE Numbering Authority (CNA)

In Exim before 4.99.2, when the SPA authentication driver is used with an adversarial SPA resource, there can be an out-of-bounds write that crashes the connection instance, or erroneous data processing that divulges data from uninitialized heap memory.

Affected Products
Vendor
EximExim
Product
Exim
Default Status
unaffected
Versions
Affected
  • From 0 before 4.99.2 (semver)
Problem Types
TypeCWE IDDescription
CWECWE-909CWE-909 Missing Initialization of Resource
Type: CWE
CWE ID: CWE-909
Description: CWE-909 Missing Initialization of Resource
Metrics
VersionBase scoreBase severityVector
3.14.8MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
Version: 3.1
Base score: 4.8
Base severity: MEDIUM
Vector:
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions
Configurations
Workarounds
Exploits
Credits
Timeline
EventDate
Replaced By
Rejected Reason
References
HyperlinkResource
https://www.openwall.com/lists/oss-security/2026/04/30/21
N/A
https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40687.assessment
N/A
https://code.exim.org/exim/exim/commit/68b963b9f75ca27b38e1c0f8c87037990199f505
N/A
https://exim.org/static/doc/security/CVE-2026-40687.txt
N/A
Hyperlink: https://www.openwall.com/lists/oss-security/2026/04/30/21
Resource: N/A
Hyperlink: https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40687.assessment
Resource: N/A
Hyperlink: https://code.exim.org/exim/exim/commit/68b963b9f75ca27b38e1c0f8c87037990199f505
Resource: N/A
Hyperlink: https://exim.org/static/doc/security/CVE-2026-40687.txt
Resource: N/A
▼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:cve@mitre.org
Published At:30 Apr, 2026 | 22:16
Updated At:01 May, 2026 | 19:17

In Exim before 4.99.2, when the SPA authentication driver is used with an adversarial SPA resource, there can be an out-of-bounds write that crashes the connection instance, or erroneous data processing that divulges data from uninitialized heap memory.

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
Secondary3.14.8MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
Primary3.19.1CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Type: Secondary
Version: 3.1
Base score: 4.8
Base severity: MEDIUM
Vector:
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
Type: Primary
Version: 3.1
Base score: 9.1
Base severity: CRITICAL
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CPE Matches
Exim
exim
>>exim>>Versions before 4.99.2(exclusive)
cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*
Weaknesses
CWE IDTypeSource
CWE-909Secondarycve@mitre.org
CWE ID: CWE-909
Type: Secondary
Source: cve@mitre.org
Evaluator Description
Evaluator Impact

Evaluator Solution

Vendor Statements
References
HyperlinkSourceResource
https://code.exim.org/exim/exim/commit/68b963b9f75ca27b38e1c0f8c87037990199f505cve@mitre.org
Patch
https://exim.org/static/doc/security/CVE-2026-40687.txtcve@mitre.org
Broken Link
https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40687.assessmentcve@mitre.org
Vendor Advisory
https://www.openwall.com/lists/oss-security/2026/04/30/21cve@mitre.org
Mailing List
Third Party Advisory
Hyperlink: https://code.exim.org/exim/exim/commit/68b963b9f75ca27b38e1c0f8c87037990199f505
Source: cve@mitre.org
Resource:
Patch
Hyperlink: https://exim.org/static/doc/security/CVE-2026-40687.txt
Source: cve@mitre.org
Resource:
Broken Link
Hyperlink: https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40687.assessment
Source: cve@mitre.org
Resource:
Vendor Advisory
Hyperlink: https://www.openwall.com/lists/oss-security/2026/04/30/21
Source: cve@mitre.org
Resource:
Mailing List
Third Party Advisory

Change History

0
Information is not available yet

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CWE ID-CWE-909
Missing Initialization of Resource
Details not found