CVE-2026-45185
Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.27% probability · 70th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- exim/exim
- Source
- cve@mitre.org
EPSS 1.3% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://code.exim.org/exim/wiki/wiki/EximSecurityVendor Advisory
- https://exim.orgProduct
- https://exim.org/static/doc/security/CVE-2026-45185.txtBroken Link
- https://exim.org/static/doc/security/EXIM-Security-2026-05-01.1/Release Notes
- https://news.ycombinator.com/item?id=48111748Issue Tracking
- https://www.openwall.com/lists/oss-security/2026/05/12/4Mailing List, Third Party Advisory
- https://xbow.com/blog/dead-letter-cve-2026-45185-xbow-found-rce-eximThird Party Advisory
- http://www.openwall.com/lists/oss-security/2026/05/12/25Mailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.