CVE•Published 2026-04-06•Modified 2026-04-07•1 article on news•6 live references•NVD data
CVE-2026-34950
Vulnerability data via NVD (ingested)
CVSS v3.1
9.1
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS percentile
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Weaknesses (CWE)
Description
fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, the publicKeyPemMatcher regex in fast-jwt/src/crypto.js uses a ^ anchor that is defeated by any leading whitespace in the key string, re-enabling the exact same JWT algorithm confusion attack that CVE-2023-48223 patched.
Timeline
Published 2026-04-06
Modified 2026-04-07
External references
Search for exposed instances
Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).
More intel sources (5)
Shodan report
vuln:CVE-2026-34950Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2026-34950Censys host search filtered to this CVE id.
grep.app
CVE-2026-34950Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2026-34950GitHub code search for direct mentions.
Google dork
"CVE-2026-34950" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.
Known PoCs on GitHub
No public proof-of-concept repositories found for CVE-2026-34950 on GitHub.