Resource exhaustion in Linuxfoundation Sigstore Timestamp Authority
CVE-2026-49835
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.
EPSS: 0.004 (37.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Linuxfoundation Sigstore_timestamp_authority
- Sigstore Timestamp-authority — versions < 2.1.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-49835?
- CVE-2026-49835 is a medium-severity vulnerability in Linuxfoundation Sigstore Timestamp Authority, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.9/10. Published 2026-07-17.
- How severe is CVE-2026-49835?
- Medium severity. CVSS v3 base score is 5.9 out of 10.