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Vulnerability record · CVE-2026-90556 · published 12 September 2026

CVE-2026-90556: Heap-based buffer overflow vulnerability

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.

8.5 CVSS 4.0 High EPSS 0.20% · top 91.0% CWE-122 · Heap-based buffer overflow Deferred
8.5CVSS 4.0 base score
0.20%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
7References
23 Sep 2026Last modified by NVD

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.

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

References

LinkTags
https://github.com/freeciv/freeciv
https://github.com/freeciv/freeciv/blob/R3_2_5/server/savegame/savegame2.c#L788
https://github.com/freeciv/freeciv/blob/R3_2_5/server/savegame/savegame3.c#L964
https://github.com/freeciv/freeciv/commit/75ecde3e86ddf2fe775768450e9a290a4f4d4387
https://github.com/freeciv/freeciv/releases/tag/R3_2_6
https://redmine.freeciv.org/issues/2161
https://www.vulncheck.com/advisories/freeciv-before-3.2.6-heap-buffer-overflow-via-worklist-load

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Source: NIST National Vulnerability Database (record CVE-2026-90556), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.