fido2-lib is vulnerable to DoS via cbor-extract heap buffer over-read in CBOR attestation parsing

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 No score.

Timeline

This record came from the full history of the GitHub Advisory Database, published 24 Mar 2026. New records show when each source confirmed them.

Sources

• GitHub Advisory Database: GHSA-g3qj-j598-cxmq
• OSV: GHSA-g3qj-j598-cxmq
• github.com/webauthn-open-source/fido2-lib/security/advisories/GHSA-g3qj-j598-cxmq
• github.com/kriszyp/cbor-extract/issues/2
• github.com/kriszyp/cbor-extract/issues/3
• github.com/kriszyp/cbor-extract/commit/1f6e0d9704149bdb5531d25f5d08a0280a71e2ca
• github.com/webauthn-open-source/fido2-lib

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.