Buffer overflow in Squirrel
CVE-2026-8258
A flaw has been found in Squirrel up to 3.2. Impacted is the function validate_format in the library sqstdlib/sqstdstring.cpp. Executing a manipulation can lead to stack-based buffer overflow. The attack can only be executed locally. The exploit has been published and may be used. The project was informed of the problem early through an issue report but has not responded yet.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.002 (5.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 5.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000
Affected products
- Squirrel — versions 3.0, 3.1, 3.2
Weakness classification (CWE)
References
- vuldb.com/vuln/362555 (technical-description, vdb-entry)
- vuldb.com/vuln/362555/cti (signature, permissions-required)
- vuldb.com/submit/809873 (third-party-advisory)
- github.com/albertodemichelis/squirrel/issues/325 (issue-tracking)
- github.com/biniamf/pocs/tree/main/squirrel-validate_format-memcpy-oob (exploit)
Frequently asked questions
- What is CVE-2026-8258?
- CVE-2026-8258 is a medium-severity vulnerability in Squirrel, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.3/10. Published 2026-05-11.
- How severe is CVE-2026-8258?
- Medium severity. CVSS v3 base score is 5.3 out of 10.