CVE-2026-90556 Freeciv before 3.2.6 Heap Buffer Overflow via worklist_load
Attackers can execute arbitrary code or cause denial of service by tricking users into loading malicious savegame files in Freeciv.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-90556?
CVE-2026-90556 is a high-severity memory corruption vulnerability in freeciv, published on 12 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
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.
Weakness: CWE-122
Which versions are affected by CVE-2026-90556?
How do I fix CVE-2026-90556?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-90556 being exploited?
There is no known exploitation of CVE-2026-90556 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-90556, GHSA-2p7g-gcvc-7p6m, UBUNTU-CVE-2026-90556.