Is CVE-2026-8258 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-8258 being exploited in the wild.

How severe is CVE-2026-8258?

Medium severity, with a CVSS score of 5.3, published 11 May 2026.

Which products and versions are affected?

Squirrel Project Squirrel up to 3.2.

Is there a fix for CVE-2026-8258?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-8258 attacked?

It is attacked with local access, in a software library.

Am I affected by CVE-2026-8258?

Check whether you run Squirrel Project Squirrel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

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

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

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.

Technologies: Squirrel Project Squirrel. Vendors: Squirrel Project.

Quick answers

Is CVE-2026-8258 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-8258 being exploited in the wild.
How severe is CVE-2026-8258?: Medium severity, with a CVSS score of 5.3, published 11 May 2026.
Which products and versions are affected?: Squirrel Project Squirrel up to 3.2.
Is there a fix for CVE-2026-8258?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-8258 attacked?: It is attacked with local access, in a software library.
Am I affected by CVE-2026-8258?: Check whether you run Squirrel Project Squirrel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

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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