CVE-2026-40687
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
02 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
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.37% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 30.9% of scored records. A rank, not a probability.
- NVD base score
- 9.1 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-06-17.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-04-30 00:00Z6 MO AGO
- Last updated
- 2026-05-01 14:25Z6 MO AGO
- Reserved
- 2026-04-14
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 4.8)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
- Weaknesses
- CWE-909Missing Initialization of ResourceClass
- Data version
- 5.2
- Document digest
- adc2a47e8b4191d89a2ef7b9488d3e1cf4ebff2708c115e74438ce8d0d2f2a82
05 Affected products
06 References
- www.openwall.comhttps://www.openwall.com/lists/oss-security/2026/04/30/21
- exim.orghttps://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40687.assessment
- code.exim.orghttps://code.exim.org/exim/exim/commit/68b963b9f75ca27b38e1c0f8c87037990199f505
- exim.orghttps://exim.org/static/doc/security/CVE-2026-40687.txt
07 Fixed in
Debian 12
- exim4 Fixed in 4.96-15+deb12u9
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- exim4 Fixed in 4.98.2-1+deb13u2
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- exim4 Fixed in 4.99.2-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- exim4 Fixed in 4.95-4ubuntu2.7
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- exim4 Fixed in 4.97-4ubuntu4.4
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 25.10
- exim4 Fixed in 4.98.2-1ubuntu2.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.04 LTS
- exim4 Fixed in 4.99.1-1ubuntu1.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- exim4 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- exim4 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 18.04 LTS
- exim4 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 20.04 LTS
- exim4 Fixed in 4.93-13ubuntu1.12+esm1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.