---
id: CVE-2026-90557
title: >-
  Freeciv versions 3.1.0 through 3.2.5 contain an out-of-bounds read
  vulnerability in sg_load_player_unit() when processing savegame files with
  invalid unit activity indices
summary: >-
  Freeciv versions 3.1.0 through 3.2.5 contain an out-of-bounds read
  vulnerability in sg_load_player_unit() when processing savegame files with
  invalid unit activity indices. An attacker can craft a malicious savegame file
  with an out-of-r…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H'
cwe:
  - CWE-125
vendor: freeciv
product: freeciv
affected:
  - freeciv >= 3.1.0 < 3.2.6
published: '2026-09-12'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T17:17:47.410'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90557'
references:
  - url: 'https://github.com/freeciv/freeciv'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/freeciv/freeciv/blob/R3_2_5/server/savegame/savegame2.c#L4282
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/freeciv/freeciv/blob/R3_2_5/server/savegame/savegame3.c#L6108
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/freeciv/freeciv/commit/ef0c76c2765fe383140eb1a70dbea1228844152e
    label: disclosure@vulncheck.com
  - url: 'https://github.com/freeciv/freeciv/releases/tag/R3_2_6'
    label: disclosure@vulncheck.com
  - url: 'https://redmine.freeciv.org/issues/2162'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/freeciv-3.1.0-through-3.2.5-out-of-bounds-read-via-savegame
    label: disclosure@vulncheck.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90557.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-90557'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-90557'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00179
epssPercentile: 0.0671
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-15T17:08:35.732761Z'
ingestedAt: '2026-09-14T15:23:07.478Z'
---

## Overview

Freeciv versions 3.1.0 through 3.2.5 contain an out-of-bounds read vulnerability in sg_load_player_unit() when processing savegame files with invalid unit activity indices. An attacker can craft a malicious savegame file with an out-of-range activity index that bypasses bounds checking and causes a crash or limited heap memory exposure when loaded.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90557.json)