Memory Buffer Bounds ErrorWeakness · CWE-119

CVE-2026-8258

MEDIUM · 5.3 CVSS v3.1 Published 2026-05-11
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
55/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Stack-based buffer overflow in Squirrel's validate_format function in sqstdlib/sqstdstring.cpp (versions up to 3.2). The function validates string formats without proper bounds checking, allowing a local attacker to overflow a stack-allocated buffer.

MitigationImplement proper bounds checking in validate_format using safe buffer handling functions or dynamic memory allocation; validate input length before any copy operations.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify if Squirrel language library is in use
    Search for Squirrel library files (libsquirrel.so, libsquirrel.a, squirrel.dll, sqstdlib.lib) or check application dependencies for squirrel references
    Affected if Squirrel library files or dependencies are found in the environment
  2. Determine installed Squirrel version
    Check version information from the Squirrel library file (e.g., strings output, file properties, or version metadata). Compare against the affected range: versions 3.2 and below
    Affected if Installed version is 3.2 or lower
  3. Verify vulnerable code path is reachable
    Review application source code or binary to determine if string formatting functions from sqstdstring library are called (e.g., sqstd_format, string formatting operations that invoke validate_format in sqstdlib/sqstdstring.cpp)
    Affected if The application uses Squirrel string formatting APIs from the standard library
  4. Inspect validate_format function usage
    If source code is available, search for calls to validate_format or string formatting functions that would trigger this code path in sqstdstring.cpp; if only binary is available, check for references to sqstd_format or related string functions
    Affected if Code paths invoking validate_format through string formatting operations are present and executable
  5. Check for custom mitigations
    Review application or library code to see if bounds checking or input validation has been implemented around string formatting operations in the Squirrel library
    Affected if No bounds checking exists in string formatting code and version is affected

Environment is affected if Squirrel library version 3.2 or lower is in use and the application executes string formatting operations that invoke the validate_format function in sqstdlib/sqstdstring.cpp.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement proper bounds checking in validate_format using safe buffer handling functions or dynamic memory allocation; validate input length before any copy operations.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-8258 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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