Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.13% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-54787High confidence
sigstore-go fails to check signature timestamps against a signing key's validity period
sigstore · sigstore-go
Official source article: GitHub GHSA-WQQC-JJCQ-VFXM ↗. Check the applicable product and release in the original source.
3.1LowCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productLow technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityLow→Operational priority:Low, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs sigstore sigstore-go and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Debian Security Tracker: 1 affected package state with no published fix
Distribution package intelligence
3 package statesRelease-specific package status
Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Package result overrides the generic status
BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 1 affected package state shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | sigstore-go | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian forkyforky · source | sigstore-go | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.2.1-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian sidsid · source | sigstore-go | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.2.1-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
Open-source package ranges2 source-attributed ranges
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| Gogithub.com/sigstore/sigstore-go | SEMVER: introduced 0; fixed 1.2.1 | 1.2.1 | OSV record ↗aggregator derived · 10 Sep 2026 |
| gogithub.com/sigstore/sigstore-go | <= 1.2.0 | 1.2.1 | GitHub advisory ↗upstream repository advisory · 31 Jul 2026 |
Direct vendor intelligence
1 currentAuthoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
CVE-2026-54787 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitygithub.com/sigstore/sigstore-go: sigstore-go: Signature bypass allows acceptance of bundles signed with expired keys
The vendor explicitly identifies these products or versions as containing the fix.
- cosign-main@aarch64 as a component of Red Hat Hardened Images
- cosign-main@src as a component of Red Hat Hardened Images
- cosign-main@x86_64 as a component of Red Hat Hardened Images
- spire1-14-main@aarch64 as a component of Red Hat Hardened Images
- spire1-14-main@src as a component of Red Hat Hardened Images
- spire1-14-main@x86_64 as a component of Red Hat Hardened Images
- spire1-15-main@aarch64 as a component of Red Hat Hardened Images
- spire1-15-main@src as a component of Red Hat Hardened Images
- spire1-15-main@x86_64 as a component of Red Hat Hardened Images
- trivy-main@aarch64 as a component of Red Hat Hardened Images
- trivy-main@src as a component of Red Hat Hardened Images
- trivy-main@x86_64 as a component of Red Hat Hardened Images
- Summary
- A flaw was found in sigstore-go, a software library used for verifying digital signatures. This vulnerability specifically affects the workflow for self-managed long-lived signing keys that do not use certificates. An attacker who possesses an expired signing key can exploit this by creating and signing software bundles that the system will incorrectly accept as valid. This bypasses the intended security checks, potentially leading to the acceptance of unauthorized or malicious software.
- Remediation
- For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
sigstore-go is a Go library for Sigstore signing and verification. Prior to 1.2.1, sigstore-go does not check a bundle signing timestamp against the validity window of an ExpiringKey wrapping a self-managed long-lived signing key without a certificate, which can allow an attacker holding expired key material to sign accepted bundles. This issue is fixed in version 1.2.1.
What
sigstore-go is a Go library for Sigstore signing and verification. Prior to 1.2.1, sigstore-go does not check a bundle signing timestamp against the validity window of an ExpiringKey wrapping a self-managed long-lived signing key without a certificate, which can allow an attacker holding expired key material to sign accepted bundles. This issue is fixed in version 1.2.1.
Why
The product uses a cryptographic key or password past its expiration date, which diminishes its safety significantly by increasing the timing window for cracking attacks against that key.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
sigstore-go is a Go library for Sigstore signing and verification. Prior to 1.2.1, sigstore-go does not check a bundle signing timestamp against the validity window of an ExpiringKey wrapping a self-managed long-lived signing key without a certificate, which can allow an attacker holding expired key material to sign accepted bundles. This issue is fixed in version 1.2.1.
Why
The product uses a cryptographic key or password past its expiration date, which diminishes its safety significantly by increasing the timing window for cracking attacks against that key.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Use of a Key Past its Expiration Date → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- High: exploitation depends on specific conditions
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-324 ↗
CWE-324: Use of a Key Past its Expiration Date. The product uses a cryptographic key or password past its expiration date, which diminishes its safety significantly by increasing the timing window for cracking attacks against that key.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.ILowIntegrity impact: A successful attack can cause a limited loss.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix availability varies by product
- Affected
- sigstore-go: < 1.2.1
- Fixed
- cosign-main@aarch64 as a component of Red Hat Hardened Images
- cosign-main@src as a component of Red Hat Hardened Images
- cosign-main@x86_64 as a component of Red Hat Hardened Images
- spire1-14-main@aarch64 as a component of Red Hat Hardened Images
- spire1-14-main@src as a component of Red Hat Hardened Images
- spire1-14-main@x86_64 as a component of Red Hat Hardened Images
- spire1-15-main@aarch64 as a component of Red Hat Hardened Images
- spire1-15-main@src as a component of Red Hat Hardened Images
- spire1-15-main@x86_64 as a component of Red Hat Hardened Images
- trivy-main@aarch64 as a component of Red Hat Hardened Images
- trivy-main@src as a component of Red Hat Hardened Images
- trivy-main@x86_64 as a component of Red Hat Hardened Images
- Action
- Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 31 Jul 2026 · Last source change 31 Jul 2026, 23:36 UTC · CWE-324 · Use of a Key Past its Expiration Date
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-51665
Product sourceCNA
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD awaiting enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.