CVE-2026-9541: Squirrel · Heap-based Buffer Overflow
Affects SquirrelSource CVE Database V5
Public exploit available · CVSS 4.8 Medium.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:PExploitation evidence
Disclosed: evidence found.
CVE published 26 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Squirrel | Affected
| Fixed in– |
GitHubalbertodemichelis/squirrelpkg:github/albertodemichelis/squirrelOther threats | Affected
| Fixed in– |
CPE configurations (1)
cpe:2.3:a:squirrel:squirrel:*:*:*:*:*:*:*:*
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AI-suggested
Users should restrict local access to trusted users only and monitor for suspicious activity. Since the vendor has not responded or issued a fix, consider applying additional local security controls such as sandboxing or running Squirrel in restricted environments until a patch is released. Check the vendor advisory regularly for updates on remediation.
Description
A security flaw has been discovered in Squirrel up to 3.2. Impacted is the function ReadObject of the file squirrel/sqobject.cpp of the component Cnut File Handler. Performing a manipulation results in heap-based buffer overflow. The attack is only possible with local access. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.