Critical 9.8Published May 12, 2026

CVE-2026-45185Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path.

Updated under an hour ago (2026-10-19 06:20 UTC)

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Exploited in the last 30 days

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: 9.8 CRITICAL (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-416
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Analyzed
Record last updated: Jun 17, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

exim exim exim:exim	from 4.97 before 4.99.3	NVD

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

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.