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TI-2026-36739 Aliases CVE-2026-49835GHSA-9c54-x2g4-v92j

Sigstore Timestamp Authority: OOM due to unbounded metric label cardinality

Priority LOW 34CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-770.

Summary

Sigstore Timestamp Authority is a service for issuing RFC 3161 timestamps. Prior to 2.1.0, the global wrapMetrics middleware records raw HTTP request path r.URL.Path and raw HTTP request method r.Method as Prometheus labels for latency and request count metric vectors before routing, allowing an unauthenticated remote attacker to issue requests with random paths such as /api/v1/timestamp/<uuid> or random HTTP methods and create unbounded permanent time-series entries that exhaust memory. This issue is fixed in version 2.1.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00744 54th percentileScored 2026-11-07
Fix Fixed timestamp-authority (sigstore): 2.1.0github.com/sigstore/timestamp-authority/v2 (Go): 2.1.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
sigstoretimestamp-authoritybefore 2.1.02.1.0Patch availableCNA
—github.com/sigstore/timestamp-authority/v2 (Go)before 2.1.02.1.0Patch availableGHSA-9c54-x2g4-v92j
—github.com/sigstore/timestamp-authority (Go)up to 1.2.9—No fix listedGHSA-9c54-x2g4-v92j
  • timestamp-authority Vendorsigstore Affected before 2.1.0 Fixed in 2.1.0 Patch available CNA
  • github.com/sigstore/timestamp-authority/v2 (Go) Vendor— Affected before 2.1.0 Fixed in 2.1.0 Patch available GHSA-9c54-x2g4-v92j
  • github.com/sigstore/timestamp-authority (Go) Vendor— Affected up to 1.2.9 Fixed in — No fix listed GHSA-9c54-x2g4-v92j

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:linuxfoundation:sigstore_timestamp_authority:*:*:*:*:*:*:*:*before 2.1.0Vulnerablebackstage
  • cpe:2.3:a:linuxfoundation:sigstore_timestamp_authority:*:*:*:*:*:*:*:* Versions before 2.1.0 Vulnerable ·backstage

Remediation

  • Fix · CNA timestamp-authority (sigstore) Fixed in 2.1.0
  • Fix · GHSA-9c54-x2g4-v92j github.com/sigstore/timestamp-authority/v2 (Go) Fixed in 2.1.0 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat Trusted Artifact Signer

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-49835
  2. 2026-10-03 Alias added: GHSA-9c54-x2g4-v92j

References

Patch 1

Advisory 1

Other 2

  • TI-2022-16356 False positive signature verification in cosign CVSS 3.1CRITICAL 9.8
  • TI-2026-36084 sigstore-js: `certificateOIDs` verification constraints are silently dropped and never enforced CVSS 3.1HIGH 7.5
  • TI-2024-19670 Cosign vulnerable to machine-wide denial of service via malicious artifacts CVSS 3.1HIGH 7.5
  • TI-2026-18290 Fulcio vulnerable to Server-Side Request Forgery (SSRF) via MetaIssuer Regex Bypass CVSS 3.1MEDIUM 5.8
  • TI-2026-36085 sigstore-js: Insufficient Verification of Data Authenticity CVSS 3.1MEDIUM 6.5
  • TI-2024-19669 Cosign vulnerable to system-wide denial of service via malicious attachments CVSS 3.1MEDIUM 5.9
See all 39 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences