What is CVE-2026-22772?

CVE-2026-22772 is a medium-severity vulnerability in Linuxfoundation Fulcio, classified under Server-Side Request Forgery (SSRF). CVSS score: 5.8/10. Published 2026-01-12.

How severe is CVE-2026-22772?

Medium severity. CVSS v3 base score is 5.8 out of 10.

SSRF in Linuxfoundation Fulcio

CVE-2026-22772

Fulcio is a certificate authority for issuing code signing certificates for an OpenID Connect (OIDC) identity. Prior to 1.8.5, Fulcio's metaRegex() function uses unanchored regex, allowing attackers to bypass MetaIssuer URL validation and…

Vulnerability class: SSRF (Server-Side Request Forgery)

EPSS: 0.002 (12.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N.

Affected products

Linuxfoundation Fulcio
Sigstore Fulcio — versions < 1.8.5

Weakness classification (CWE)

CWE-918 — Server-Side Request Forgery (SSRF)

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)

Frequently asked questions

What is CVE-2026-22772?: CVE-2026-22772 is a medium-severity vulnerability in Linuxfoundation Fulcio, classified under Server-Side Request Forgery (SSRF). CVSS score: 5.8/10. Published 2026-01-12.
How severe is CVE-2026-22772?: Medium severity. CVSS v3 base score is 5.8 out of 10.