CVE-2026-49835

Sigstore Timestamp Authority: OOM due to unbounded metric label cardinality

Published Jul 17, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-9c54-x2g4-v92j Sigstore Timestamp Authority has OOM due to unbounded metric label cardinality
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A flaw was found in Sigstore Timestamp Authority. An unauthenticated remote attacker can exploit this vulnerability by sending requests with arbitrary HTTP paths and methods. This leads to the creation of an excessive number of unique metric labels, causing unbounded memory growth and a denial of service (DoS) condition on the server. This issue is a type of Improper Restriction of Resource Consumption (CWE-770). 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.
Title timestamp-authority: Sigstore Timestamp Authority: Denial of Service via unbounded metric label cardinality Sigstore Timestamp Authority: OOM due to unbounded metric label cardinality
References
Type Values Removed Values Added
Description A flaw was found in Sigstore Timestamp Authority. An unauthenticated remote attacker can exploit this vulnerability by sending requests with arbitrary HTTP paths and methods. This leads to the creation of an excessive number of unique metric labels, causing unbounded memory growth and a denial of service (DoS) condition on the server. This issue is a type of Improper Restriction of Resource Consumption (CWE-770).
Title timestamp-authority: Sigstore Timestamp Authority: Denial of Service via unbounded metric label cardinality
Weaknesses CWE-770
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 17, 2026, 7:45 PM
Reserved
Jun 1, 2026, 6:50 PM
Status
Analyzed
Published
Jul 17, 2026, 7:17 PM
Modified
Oct 24, 2026, 8:10 PM
Severity
Moderate
Public date
Jun 30, 2026, 6:40 PM