CVE-2026-40687
Detail
Description
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.
Metrics
NVD enrichment efforts reference publicly available information to associate
vector strings. CVSS information contributed by other sources is also
displayed.
CVSS 4.0 Severity and Vector Strings:
NVD assessment
not yet provided.
CVSS 3.x Severity and Vector Strings:
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
CVSS 2.0 Severity and Vector Strings:
Base
Score:
NVD assessment
not yet provided.
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Weakness Enumeration
| CWE-ID |
CWE Name |
Source |
|
CWE-909
|
Missing Initialization of Resource |
MITRE
|
Change History
5 change records found show changes
CVE Modified by CISA-ADP
6/17/2026 6:45:34 AM
| Action |
Type |
Old Value |
New Value |
| Added |
SSVC |
{"timestamp":"2026-05-01T14:25:03.813157Z","id":"CVE-2026-40687","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}
|
CVE Modified by MITRE
6/17/2026 6:45:34 AM
| Action |
Type |
Old Value |
New Value |
| Added |
Affected |
[{"vendor":"Exim","product":"Exim","defaultStatus":"unaffected","versions":[{"version":"0","lessThan":"4.99.2","versionType":"semver","status":"affected"}]}]
|
Initial Analysis by NIST
5/01/2026 3:17:51 PM
| Action |
Type |
Old Value |
New Value |
| Added |
CVSS V3.1 |
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
|
| Added |
CPE Configuration |
OR
*cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:* versions up to (excluding) 4.99.2
|
| Added |
Reference Type |
MITRE: https://code.exim.org/exim/exim/commit/68b963b9f75ca27b38e1c0f8c87037990199f505 Types: Patch
|
| Added |
Reference Type |
MITRE: https://exim.org/static/doc/security/CVE-2026-40687.txt Types: Broken Link
|
| Added |
Reference Type |
MITRE: https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40687.assessment Types: Vendor Advisory
|
| Added |
Reference Type |
MITRE: https://www.openwall.com/lists/oss-security/2026/04/30/21 Types: Mailing List, Third Party Advisory
|
CVE Modified by MITRE
4/30/2026 10:16:04 PM
| Action |
Type |
Old Value |
New Value |
| Added |
Reference |
https://exim.org/static/doc/security/CVE-2026-40687.txt
|
| Removed |
Reference |
https://exim.org/static/doc/security/CVE-2025-40687.txt
|
New CVE Received from MITRE
4/30/2026 6:16:25 PM
| Action |
Type |
Old Value |
New Value |
| Added |
Description |
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.
|
| Added |
CVSS V3.1 |
AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
|
| Added |
CWE |
CWE-909
|
| Added |
Reference |
https://code.exim.org/exim/exim/commit/68b963b9f75ca27b38e1c0f8c87037990199f505
|
| Added |
Reference |
https://exim.org/static/doc/security/CVE-2025-40687.txt
|
| Added |
Reference |
https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40687.assessment
|
| Added |
Reference |
https://www.openwall.com/lists/oss-security/2026/04/30/21
|
Quick Info
CVE Dictionary Entry: CVE-2026-40687 NVD
Published Date: 04/30/2026 NVD
Last Modified: 06/17/2026
Source: MITRE
|
