CVE-2026-22772
Fulcio is vulnerable to Server-Side Request Forgery (SSRF) via MetaIssuer Regex Bypass in github.com/sigstore/fulcio
Description
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 trigger SSRF to arbitrary internal services. Since the SSRF only can trigger GET requests, the request cannot mutate state. The response from the GET request is not returned to the caller so data exfiltration is not possible. A malicious actor could attempt to probe an internal network through Blind SSRF. This vulnerability is fixed in 1.8.5.
How to fix CVE-2026-22772
To remediate CVE-2026-22772, upgrade the affected package to a fixed version below.
- —no fix listed
- —upgrade to 1.8.5 or later
- —upgrade to 1.8.5 or later
Is CVE-2026-22772 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0
- from 0, < 1.8.5
- from 0, < 1.8.5
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N |