Vulnerability · Published Jul 17, 2026 · Assigned by GitHub_M

CVE-2026-49835Sigstore Timestamp Authority: OOM due to unbounded metric label cardinality

Medium 5.9

In plain English

A medium-severity resource allocation without limits in timestamp-authority from sigstore. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 55% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.9Medium

Exploit odds (30 days)0.7%top 45.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:13	golang-github-sigstore-timestamp-authority	no fix listed	DEBIAN-CVE-2026-49835
Debian:14	golang-github-sigstore-timestamp-authority	2.1.0-1	DEBIAN-CVE-2026-49835
Go	github.com/sigstore/timestamp-authority	no fix listed	GO-2026-5851
Go	github.com/sigstore/timestamp-authority	no fix listed	GHSA-9c54-x2g4-v92j
Go	github.com/sigstore/timestamp-authority/v2	2.1.0	GHSA-9c54-x2g4-v92j
Go	github.com/sigstore/timestamp-authority/v2	2.1.0	GO-2026-5851
Ubuntu:26.04:LTS	golang-github-sigstore-timestamp-authority	no fix listed	UBUNTU-CVE-2026-49835
Ubuntu:26.10	golang-github-sigstore-timestamp-authority	no fix listed	UBUNTU-CVE-2026-49835

Affected products (as reported)

Vendor	Product	Versions
sigstore	timestamp-authority	< 2.1.0

Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

References

https://github.com/sigstore/timestamp-authority/security/advisories/GHSA-9c54-x2g4-v92j x_refsource_CONFIRM
https://github.com/sigstore/timestamp-authority/commit/506ec57b6ac2ea1e4739322e47453469425b69b5 x_refsource_MISC
https://github.com/sigstore/timestamp-authority/releases/tag/v2.1.0 x_refsource_MISC