Vulnerability · Published Sep 12, 2026 · Assigned by VulnCheck

CVE-2026-90556Freeciv before 3.2.6 Heap Buffer Overflow via worklist_load

High 7.8

In plain English

A high-severity heap buffer overflow in freeciv from freeciv. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.8High

Exploit odds (30 days)0.2%top 89.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Freeciv versions before 3.2.6 contain a heap buffer overflow in worklist_load() when processing savegame files with declared worklist lengths exceeding the fixed array bound of 64 elements. Attackers can craft malicious savegame files that write past the entries array into adjacent heap-allocated struct fields, potentially corrupting memory when a user or server operator loads the file.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	freeciv	no fix listed	DEBIAN-CVE-2026-90556
Debian:13	freeciv	no fix listed	DEBIAN-CVE-2026-90556
Debian:14	freeciv	3.2.6+ds-1	DEBIAN-CVE-2026-90556
Ubuntu:26.04:LTS	freeciv	no fix listed	UBUNTU-CVE-2026-90556

Affected products (as reported)

Vendor	Product	Versions
freeciv	freeciv	0 – before 3.2.6

Weakness: CWE-122 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References

Patch Commit patch
https://github.com/freeciv/freeciv product
https://redmine.freeciv.org/issues/2161 issue-tracking
https://github.com/freeciv/freeciv/blob/R3_2_5/server/savegame/savegame3.c#L964 technical-description
freeciv R3_2_6 Release Notes release-notes
https://github.com/freeciv/freeciv/blob/R3_2_5/server/savegame/savegame2.c#L788 technical-description
VulnCheck Advisory: Freeciv before 3.2.6 Heap Buffer Overflow via worklist_load third-party-advisory