Junglewise Threat Intelligence

CVE-2026-8258: Squirrel stack overflow in validate_format function

CVE-2026-8258 · Severity: medium · CVSS 5.3 · Published 2026-05-11

Technologies: Squirrel Project Squirrel. Vendors: Squirrel Project.

Executive brief

A security flaw exists in the Squirrel programming language, a lightweight scripting engine used in various software and games. A local attacker can exploit this vulnerability to cause a system crash or potentially execute unauthorized code by providing specially crafted input. This could lead to a disruption of service or unauthorized access to data on the affected system.

Technical details

A stack-based buffer overflow vulnerability exists in Squirrel up to version 3.2 within the 'validate_format' function of the 'sqstdlib/sqstdstring.cpp' library. The root cause is an off-by-one error during length checks when processing format strings. A local attacker with low privileges can trigger this overflow by passing a manipulated string to the affected function, potentially leading to arbitrary code execution or a denial of service. While a Proof-of-Concept (PoC) exploit has been published, the project maintainers have not yet released an official patch.

Affected products

  • Squirrel Project Squirrel up to 3.2

Timeline

  • 2026-05-11: disclosed: Vulnerability disclosed and CVE assigned
  • 2026-05-11: advisory: VulDB and NVD published advisory

References

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