CVE-2026-42006
4.3
MEDIUM
CVSS 3.1
EPSS 0.45%
Description
An attacker can cause uncontrolled memory usage with excessive bracing over IMAP. The fix in CVE-2026-27857 was incomplete, only blocking one way of doing this, so there was still another way left open. In particular, the fix was for closing braces, but you could still use open braces to bypass the limit. Using excessive bracing, attacker can cause memory usage up to configured memory limit. Install fixed version, or configure vsz_limit for imap process to low value. No publicly available exploits are known.
How to fix CVE-2026-42006
To remediate CVE-2026-42006, upgrade the affected package to a fixed version below.
- —upgrade to 1:2.3.13+dfsg1-2+deb11u4 or later
Is CVE-2026-42006 being exploited?
Low — EPSS is 0.5%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 1:2.3.13+dfsg1-2+deb11u4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |