Description
fetchmail 4.6.3 through 6.3.16, when debug mode is enabled, does not properly handle invalid characters in a multi-character locale, which allows remote attackers to cause a denial of service (memory consumption and application crash) via a crafted (1) message header or (2) POP3 UIDL list.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | fetchmail | 6.3.16-2 | — |
| Debian 13 | fetchmail | 6.3.16-2 | — |
| Debian 12 | fetchmail | 6.3.16-2 | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | fetchmail | 6.3.26-13.4 | openSUSE-SU-2024:10194-1 |
Advisories 1
- openSUSE-SU-2024:10194-1 fetchmail-6.3.26-13.4 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026