github.com/sigstore/timestamp-authority/v2

CVE-2026-49835

CVE-2026-49835 is a medium-severity allocation of resources without limits or throttling vulnerability in github.com/sigstore/timestamp-authority/v2 (go), affecting versions <= 2.0.6. It is fixed in 2.1.0.

Key facts
CVSS score
5.9
Medium
Attack vector
Network
Issuing authority
GitHub Advisory Database
Affected package
github.com/sigstore/timestamp-authority/v2
Fixed in
2.1.0
Disclosed
2026

Summary

Impact An unauthenticated remote attacker can trigger unbounded memory growth on the timestamp authority server. This vulnerability exists because the global wrapMetrics middleware records the raw HTTP request path (r.URL.Path) and raw HTTP request method (r.Method) as Prometheus labels for latency and request count metric vectors. Since this middleware runs before standard routing occurs, it executes for all incoming requests, including those for unmatched paths (yielding 404 responses) or arbitrary request methods. The Prometheus library registers a new, permanent time-series entry for every distinct label combination. An attacker can continuously issue requests containing random paths (e.g., /api/v1/timestamp/<uuid>) or random HTTP methods to exhaust system memory. Patches This issue has been patched by limiting the metric label values to a strict allowlist of expected paths (/ping, /api/v1/timestamp, /api/v1/timestamp/certchain) and expected HTTP methods (GET, POST, HEAD, OPTIONS). Unrecognized paths or methods are normalized to a static string ("unrecognized"). Users should update to version v2.0.7 or later. Workarounds Block or drop incoming requests with invalid HTTP methods or unknown request paths at a reverse proxy or load balancer before they reach the timestamp authority server. Configure rate-limiting on the public interface to prevent remote attackers from issuing millions of unique requests in a short duration.

Impact

What is allocation of resources without limits or throttling?

The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.

Severity and exposure

CVE-2026-49835 has a CVSS score of 5.9 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.

A fixed version is available (2.1.0). Upgrading removes the vulnerable code path.

Affected versions

go

  • github.com/sigstore/timestamp-authority/v2 (<= 2.0.6)
  • github.com/sigstore/timestamp-authority (<= 1.2.9)

Security releases

  • github.com/sigstore/timestamp-authority/v2 → 2.1.0 (go)
Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.

Kodem's runtime-powered SCA identifies whether CVE-2026-49835 is reachable in your applications. Explore open-source security for your team.

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Remediation advice

Upgrade github.com/sigstore/timestamp-authority/v2 to 2.1.0 or later to resolve this vulnerability.

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently asked questions about CVE-2026-49835

What is CVE-2026-49835?

CVE-2026-49835 is a medium-severity allocation of resources without limits or throttling vulnerability in github.com/sigstore/timestamp-authority/v2 (go), affecting versions <= 2.0.6. It is fixed in 2.1.0. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.

How severe is CVE-2026-49835?

CVE-2026-49835 has a CVSS score of 5.9 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which packages are affected by CVE-2026-49835?
  • github.com/sigstore/timestamp-authority/v2 (go) (versions <= 2.0.6)
  • github.com/sigstore/timestamp-authority (go) (versions <= 1.2.9)
Is there a fix for CVE-2026-49835?

Yes. CVE-2026-49835 is fixed in 2.1.0. Upgrade to this version or later.

Is CVE-2026-49835 exploitable, and should I be worried?

Whether CVE-2026-49835 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo

What actually determines whether CVE-2026-49835 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2026-49835?

Upgrade github.com/sigstore/timestamp-authority/v2 to 2.1.0 or later.

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