CVE-2026-22772
mediumpriority · track · 21EPSS 0.002 · 14 %ileDEEUUSEPSS · scored 2026-10-27
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.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- Fixedvexctl-0:0.4.1+git78.f951e3a-150000.1.11.1.aarch64 as component of openSUSE Leap 15.6suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedvexctl-0:0.4.1+git78.f951e3a-150000.1.11.1.ppc64le as component of openSUSE Leap 15.6suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedvexctl-0:0.4.1+git78.f951e3a-150000.1.11.1.s390x as component of openSUSE Leap 15.6suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedvexctl-0:0.4.1+git78.f951e3a-150000.1.11.1.x86_64 as component of openSUSE Leap 15.6suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-150400.3.35.1.aarch64 as component of SUSE Linux Enterprise Module for Basesystem 15 SP7suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-150400.3.35.1.aarch64 as component of openSUSE Leap 15.6suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-150400.3.35.1.ppc64le as component of SUSE Linux Enterprise Module for Basesystem 15 SP7suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-150400.3.35.1.ppc64le as component of openSUSE Leap 15.6suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-150400.3.35.1.s390x as component of SUSE Linux Enterprise Module for Basesystem 15 SP7suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-150400.3.35.1.s390x as component of openSUSE Leap 15.6suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-150400.3.35.1.x86_64 as component of SUSE Linux Enterprise Module for Basesystem 15 SP7suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-150400.3.35.1.x86_64 as component of openSUSE Leap 15.6suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-bash-completion-0:3.0.5-150400.3.35.1.noarch as component of SUSE Linux Enterprise Module for Basesystem 15 SP7suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-zsh-completion-0:3.0.5-150400.3.35.1.noarch as component of SUSE Linux Enterprise Module for Basesystem 15 SP7suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-160000.1.1.aarch64 as component of SUSE Linux Enterprise Server 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-160000.1.1.aarch64 as component of SUSE Linux Enterprise Server for SAP applications 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-160000.1.1.ppc64le as component of SUSE Linux Enterprise Server 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-160000.1.1.ppc64le as component of SUSE Linux Enterprise Server for SAP applications 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-160000.1.1.s390x as component of SUSE Linux Enterprise Server 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-160000.1.1.s390x as component of SUSE Linux Enterprise Server for SAP applications 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-160000.1.1.x86_64 as component of SUSE Linux Enterprise Server 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-160000.1.1.x86_64 as component of SUSE Linux Enterprise Server for SAP applications 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedhauler-0:1.4.1-bp160.1.1.aarch64 as component of openSUSE Leap 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedhauler-0:1.4.1-bp160.1.1.x86_64 as component of openSUSE Leap 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedhauler-0:1.4.1-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedhauler-0:1.4.1-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedhauler-0:1.4.1-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedhauler-0:1.4.1-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedvexctl-0:0.4.1+git78.f951e3a-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedvexctl-0:0.4.1+git78.f951e3a-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedvexctl-0:0.4.1+git78.f951e3a-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedvexctl-0:0.4.1+git78.f951e3a-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-bash-completion-0:3.0.5-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-bash-completion-0:3.0.5-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-bash-completion-0:3.0.5-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-bash-completion-0:3.0.5-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-fish-completion-0:3.0.5-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-fish-completion-0:3.0.5-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-fish-completion-0:3.0.5-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-fish-completion-0:3.0.5-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-zsh-completion-0:3.0.5-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-zsh-completion-0:3.0.5-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-zsh-completion-0:3.0.5-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-zsh-completion-0:3.0.5-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-160000.1.1.aarch64 as component of openSUSE Leap 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-160000.1.1.ppc64le as component of openSUSE Leap 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-160000.1.1.s390x as component of openSUSE Leap 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-0:3.0.5-160000.1.1.x86_64 as component of openSUSE Leap 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-bash-completion-0:3.0.5-160000.1.1.noarch as component of openSUSE Leap 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-fish-completion-0:3.0.5-160000.1.1.noarch as component of openSUSE Leap 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcosign-zsh-completion-0:3.0.5-160000.1.1.noarch as component of openSUSE Leap 16.0suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
advisories (10)
Vendor and ecosystem advisories describing this.
- SUSE-SU-2026:0592-1Security update for vexctl2026-02-20csaf · suse_csafDE
Security update for vexctl
- SUSE-SU-2026:0777-1Security update for cosign2026-03-03csaf · suse_csafDE
Security update for cosign
- SUSE-SU-2026:20904-1Security update for cosign2026-03-18csaf · suse_csafDE
Security update for cosign
- openSUSE-RU-2026:20161-1Recommended update for hauler2026-01-27csaf · suse_csafDE
Recommended update for hauler
- openSUSE-SU-2026:10068-1hauler-1.4.1-1.1 on GA media2026-01-19csaf · suse_csafDE
hauler-1.4.1-1.1 on GA media
- openSUSE-SU-2026:10230-1vexctl-0.4.1+git78.f951e3a-1.1 on GA media2026-02-19csaf · suse_csafDE
vexctl-0.4.1+git78.f951e3a-1.1 on GA media
- openSUSE-SU-2026:10235-1cosign-3.0.5-1.1 on GA media2026-02-23csaf · suse_csafDE
cosign-3.0.5-1.1 on GA media
- openSUSE-SU-2026:20386-1Security update for cosign2026-03-18csaf · suse_csafDE
Security update for cosign
- GHSA-59jp-pj84-45mrFulcio is vulnerable to Server-Side Request Forgery (SSRF) via MetaIssuer Regex Bypass2026-01-13ghsa · osvUS
# Security Disclosure: SSRF via MetaIssuer Regex Bypass ## Summary 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](https://portswigger.net/web-security/ssrf/blind). ## Impact - SSRF to cloud metadata (169.254.169.254) - SSRF to internal Kubernetes APIs - SSRF to any service accessible from Fulcio's network - Affects ALL deployments using MetaIssuers ## Patches Upgrade to v1.8.5. ## Workarounds None. If anchors are included in the meta issuer configuration URL, they will be escaped before the regular expression is compiled, not making this a sufficient mitigation. Deployments must upgrade to the latest Fulcio release v1.8.5. ## Affected Code **File**: `pkg/config/config.go` **Function**: `metaRegex()` (lines 143-156) ```go func metaRegex(issuer string) (*regexp.Regexp, error) { quoted := regexp.QuoteMeta(issuer) replaced := strings.ReplaceAll(quoted, regexp.QuoteMeta("*"), "[-_a-zA-Z0-9]+") return regexp.Compile(replaced) // Missing ^ and $ anchors } ``` ## The Bug The regex has no `^` (start) or `$` (end) anchors. Go's `regexp.MatchString()` does substring matching, so: ``` Pattern: https://oidc.eks.*.amazonaws.com/id/* Regex: https://oidc\.eks\.[-_a-zA-Z0-9]+\.amazonaws\.com/id/[-_a-zA-Z0-9]+ Input: https://attacker.com/x/https://oidc.eks.foo.amazonaws.com/id/bar Result: MATCHES (substring found) ``` ## Exploit 1. Attacker sends JWT with `iss` claim: `https://attacker.com/path/https://oidc.eks.x.amazonaws.com/id/y` 2. Fulcio's `GetIssuer()` matches this against MetaIssuer patterns 3. Unanchored regex matches the embedded pattern as substring 4. Fulcio calls `oidc.NewProvider()` with attacker's URL 5. HTTP request goes to `attacker.com`, not `amazonaws.com` 6. Attacker returns OIDC discovery with `jwks_uri` pointing to internal service 7. Fulcio fetches from internal service → SSRF
- GO-2026-4311Fulcio is vulnerable to Server-Side Request Forgery (SSRF) via MetaIssuer Regex Bypass in github.com/sigstore/fulcio2026-01-23vendor · osvUS
Fulcio is vulnerable to Server-Side Request Forgery (SSRF) via MetaIssuer Regex Bypass in github.com/sigstore/fulcio
also known as (5)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (8)
External citations — patches, advisories, analysis.
- https://github.com/sigstore/fulcio/commit/eaae2f2be56df9dea5f9b439ec81bedae4c0978dcnnvd
- https://github.com/sigstore/fulcio/releasesPatchcnnvd
- https://github.com/sigstore/fulcio/security/advisories/GHSA-59jp-pj84-45mrcnnvd
- https://vigilance.fr/vulnerability/Fulcio-Server-Side-Request-Forgery-via-MetaIssuer-URL-Validation-49760cnnvd
- https://github.com/sigstore/fulcio/commit/eaae2f2be56df9dea5f9b439ec81bedae4c0978denisa_euvd
- https://github.com/sigstore/fulcio/security/advisories/GHSA-59jp-pj84-45mrenisa_euvd
- https://github.com/sigstore/fulcio/commit/eaae2f2be56df9dea5f9b439ec81bedae4c0978dPatchnvd
- https://github.com/sigstore/fulcio/security/advisories/GHSA-59jp-pj84-45mrExploitVendor Advisorynvd
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