CVE-2026-40684
In Exim before 4.99.2, on systems using musl libc (not glibc), an attacker can crash the connection instance when malformed DNS data is present in PTR records. This is caused by a dn_expand oddity in octal printing.
Scoring
- Severity
- MEDIUM
- CVSS base score
- 5.9
- CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS probability
- 0.36%
- CWE
- CWE-684
- Published
- 2026-04-30
- Last modified
- 2026-05-01
Affected products
- Exim Exim
Weakness type
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