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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| sigstore | fulcio | < 1.8.5 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | golang-github-sigstore-fulcio | 1.8.5-1 | — |
| Debian 13 | golang-github-sigstore-fulcio | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | golang-github-sigstore-fulcio | No fix yet | — |
| Ubuntu 26.04 LTS | golang-github-sigstore-fulcio | No fix yet | — |
| Ubuntu 25.10 | golang-github-sigstore-fulcio | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | cosign | 3.0.5-150400.3.35.1 | SUSE-SU-2026:0777-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | cosign | 3.0.5-160000.1.1 | SUSE-SU-2026:20904-1 |
| SLES 16.0 | cosign | 3.0.5-160000.1.1 | SUSE-SU-2026:20904-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | cosign | 3.0.5-1.1 | openSUSE-SU-2026:10235-1 |
| openSUSE Tumbleweed | hauler | 1.4.1-1.1 | openSUSE-SU-2026:10068-1 |
| openSUSE Tumbleweed | vexctl | 0.4.1+git78.f951e3a-1.1 | openSUSE-SU-2026:10230-1 |
| openSUSE Leap 16.0 | cosign | 3.0.5-160000.1.1 | openSUSE-SU-2026:20386-1 |
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260723T184607-160000.1.1 | openSUSE-SU-2026:21483-1 |
| openSUSE Leap 16.0 | hauler | 1.4.1-bp160.1.1 | openSUSE-RU-2026:20161-1 |
| openSUSE Leap 16.0 | vexctl | 0.4.4+git20.5d61136-160000.1.1 | openSUSE-SU-2026:21481-1 |
| openSUSE Leap 15.6 | cosign | 3.0.5-150400.3.35.1 | SUSE-SU-2026:0777-1 |
| openSUSE Leap 15.6 | govulncheck-vulndb | 0.0.20260123T022811-150000.1.140.1 | SUSE-SU-2026:0292-1 |
| openSUSE Leap 15.6 | vexctl | 0.4.1+git78.f951e3a-150000.1.11.1 | SUSE-SU-2026:0592-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | runfinch-finch | 1.15.1-1.amzn2023.0.1 | ALAS2023-2026-1507 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | aactl | 0.4.12-r41 | — |
| Wolfi rolling | cosign | 3.0.4-r1 | — |
| Wolfi rolling | falco-no-driver | 0.43.0-r1 | — |
| Wolfi rolling | falcoctl | 0.12.0-r0 | — |
| Wolfi rolling | gitsign +1 | 0.14.0-r0 | — |
| Wolfi rolling | kots | 1.129.3-r0 | — |
| Wolfi rolling | kubescape | 3.0.48-r0 | — |
| Wolfi rolling | sigstore-scaffolding-ctlog-verifyfulcio +2 | 0.7.31-r4 | — |
| Wolfi rolling | skopeo | 1.21.0-r2 | — |
| Wolfi rolling | slsa-verifier | 2.7.1-r6 | — |
| Wolfi rolling | tekton-chains | 0.26.0-r5 | — |
| Wolfi rolling | vexctl | 0.4.1-r5 | — |
| Wolfi rolling | witness | 0.10.2-r0 | — |
| Wolfi rolling | zarf | 0.70.1-r0 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/sigstore/fulcio | < 1.8.5 | 1.8.5 | GHSA-59jp-pj84-45mr |
Advisories 12
- openSUSE-SU-2026:21483-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Jul 31, 2026
- openSUSE-SU-2026:21481-1 Security update for vexctl SUSE / openSUSE Security Updates · Jul 31, 2026
- SUSE-SU-2026:20904-1 Security update for cosign SUSE / openSUSE Security Updates · Apr 2, 2026
- ALAS2023-2026-1507 Moderate: runfinch-finch security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Apr 1, 2026
- openSUSE-SU-2026:20386-1 Security update for cosign SUSE / openSUSE Security Updates · Mar 26, 2026
- openSUSE-SU-2026:10235-1 cosign-3.0.5-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2026:10230-1 vexctl-0.4.1+git78.f951e3a-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2026:10068-1 hauler-1.4.1-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-RU-2026:20161-1 Recommended update for hauler SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0292-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0777-1 Security update for cosign SUSE / openSUSE Security Updates · Mar 4, 2026
- SUSE-SU-2026:0592-1 Security update for vexctl SUSE / openSUSE Security Updates · Feb 21, 2026