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. It is triggered when a client...
- Published
- May 12, 2026
- Updated
- May 14, 2026
- Assigning CNA
- mitre
- Evidence observed
- Aug 8, 2026
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HLow · next 30 days
- Percentile
- 60.4%
- Model date
- Oct 17, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
Summary
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.
Sources
- CVE-2026-45185Exploit
Exploits a critical pre-auth heap use-after-free in Exim via TLS close_notify to gain remote root; includes a GDB lab harness and Nuclei detection template.
- cve-2026-45185-detection-scriptDetection
These detection scripts are property of the SECPlayground Platform. Two safe detection scripts. Neither drives the close_notify-mid-BDAT trigger, so they will not crash the daemon or leave panic-log entries. Both verdicts are "likely vulnerable" — distinguishing GnuTLS from OpenSSL builds remotely is not reliable without exploitation.
POC_CVE-2026-45185 for nuclei-templates
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