CVE-2026-45185

Name: CVE-2026-45185
Creator: NVD / NIST
Published: 2026-05-12T20:16:46.137+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.23%

Last modified Jun 17, 2026

CVE-2026-45185 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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. EPSS estimates a 1.23% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.23%

65.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

Affected Software

Vendor	Product	Versions
Exim	Exim	>= 4.97, < 4.99.3

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

Timeline

Published: May 12, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-45185?

How severe is CVE-2026-45185?

CVE-2026-45185 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.23% probability of exploitation in the next 30 days.

How do I fix CVE-2026-45185?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-45185?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST