Steeltoe: Header-forwarded client cert lacks proof of private-key possession

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.0025, the 16th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 31 Oct 2026, 15:21 UTC First seen by agentprime
2. 31 Oct 2026, 15:21 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-5mq7-rwhj-4fh9
• OSV: GHSA-5mq7-rwhj-4fh9
• github.com/SteeltoeOSS/security-advisories/security/advisories/GHSA-5mq7-rwhj-4fh9
• nvd.nist.gov/vuln/detail/CVE-2026-81868
• github.com/SteeltoeOSS/Steeltoe/commit/b626ef3d60aaf19c68eeeed5ee81045406c8c6d0
• github.com/SteeltoeOSS/Steeltoe/releases/tag/4.3.0
• github.com/SteeltoeOSS/security-advisories

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.