ANT-2026-SBF8X04Q · selinux

type-confusion medium

Severity Claude medium · Security research firm medium · Maintainer -

Discovered by Claude Mythos Preview

REPORT

Anthropic's analysis, sealed at approval. Disclosure to the maintainer was performed by Trail of Bits.

ANT-2026-SBF8X04Q: Type confusion in CIL sensitivity alias resolution causing heap buffer overflow via alias struct cast to sensitivity struct

An alias struct is incorrectly cast to a sensitivity struct during CIL sensitivity alias resolution, producing a type-confused pointer and resulting in a heap buffer overflow.

Target

Project: selinux
Location: CIL sensitivity alias resolution
Discovery: static analysis — not yet dynamically reproduced

Reproduction

This finding was identified by static analysis and has not yet been dynamically reproduced. A trigger input is not included.

[No reproducer or sanitizer output attached — request from security-cvd@anthropic.com if needed.]

Acknowledgement

This vulnerability was discovered by Claude, Anthropic's AI assistant, and triaged by the Anthropic security team in collaboration with Anthropic Research. Please direct questions to security-cvd@anthropic.com and reference ANT-2026-SBF8X04Q.

Reference: ANT-2026-SBF8X04Q
Anthropic CVD Policy: https://www.anthropic.com/coordinated-vulnerability-disclosure

SECURITY RESEARCH FIRM ANALYSIS

Triage and disclosure were performed by Trail of Bits.

Verdict: true positive
Severity: medium

TIMELINE

Dates from discovery through public reveal.

2026-03-29 Reported to tracker
2026-04-09 Sent to maintainer
2026-05-07 Maintainer acknowledged
2026-07-01 Patch released
2026-08-17 Publicly revealed

PROVENANCE

SHA-3-512 hash:

a2ad4e6ef78782ef1f99b0a4a531f4cfc0fdd97ed1acd6af61dfb4a6c1d9566da5bc161c8c2acf5058c8af7a464faa5e01195150eafbec9ffd505212eefb8932

Committed 2026-04-09 11:50 PT

Revealed 2026-08-17 13:03 PT

Verify (download preimage.json)

Show preimage JSON

{
  "ant_id": "ANT-2026-SBF8X04Q",
  "bug_class": "Type Confusion",
  "claude_severity": "medium",
  "commit_sha": null,
  "created_at": "2026-03-29T20:43:26+00:00",
  "description": "An alias struct is incorrectly cast to a sensitivity struct during CIL sensitivity alias resolution, producing a type-confused pointer and resulting in a heap buffer overflow.",
  "discovered_at": null,
  "location": "CIL sensitivity alias resolution",
  "poc_sha256": null,
  "preimage_version": 1,
  "project": "SELinux",
  "reproduction": null,
  "technical_details": null,
  "title": "Type confusion in CIL sensitivity alias resolution causing heap buffer overflow via alias struct cast to sensitivity struct",
  "vendor_severity": "medium"
}