# CVE-2026-49835: Sigstore Timestamp Authority: OOM due to unbounded metric label cardinality > An unauthenticated attacker can exhaust server memory by sending requests with random paths and methods, causing a denial of service. - **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 17 Jul 2026 - **Updated:** 17 Jul 2026 - **Also known as:** CLEANSTART-2026-MR47110, CLEANSTART-2026-NV69611, CLEANSTART-2026-ZX16649, DEBIAN-CVE-2026-49835, GHSA-9c54-x2g4-v92j, GO-2026-5851, MINI-23c3-cf4v-6xpw, MINI-2772-pp3p-hcgx, MINI-28r7-gr5q-63rj, MINI-2hcr-h88g-4h2h, MINI-2mhp-gw8x-wh54, MINI-2rfv-mw4q-hc2f, MINI-2x8c-pgcm-r7x5, MINI-2xv8-7mvp-ffjc, MINI-3ph5-xx6w-2vj6, MINI-3q2r-cfhh-w4cr, MINI-3r87-396f-cq27, MINI-456h-9h3v-hch8, MINI-4gv8-x8cw-542x, MINI-4jh7-9cp6-vvrv, MINI-4vpp-8wcr-w6jh, MINI-4w6w-6v54-j4c8, MINI-5jp4-xhq9-g5r3, MINI-5pvr-8m2q-cqjx, MINI-6gv6-gvfg-wgp6, MINI-7793-73hf-jr8f, MINI-79wh-5864-g67x, MINI-7pf4-2qpx-5mj4, MINI-7vc7-m3vr-h7qc, MINI-868j-77h2-w22r, MINI-8fg2-gcp5-mffh, MINI-9fhw-pr3v-m525, MINI-9jq2-mv3j-rpv6, MINI-c5vx-v5mq-5qw2, MINI-f9h9-4gjg-2hw5, MINI-fxcf-2prj-92f2, MINI-g456-hwq4-6x6p, MINI-g7cg-8vmv-wx4r, MINI-h99x-6cph-5gx6, MINI-j63j-f63c-mjmx, MINI-j8x3-5p35-xrfp, MINI-jg46-wxwv-j57v, MINI-jr79-h58w-cw22, MINI-jvmx-7m7j-wrrp, MINI-m2pf-gq6v-52xh, MINI-mrr7-hjhx-7m62, MINI-mw23-7j6v-ghrm, MINI-mwqw-877m-j57r, MINI-p4qf-qf94-3f75, MINI-pcgg-q633-jm22, MINI-q55v-gf5r-hwpw, MINI-q6mf-cf9r-grwg, MINI-qmg7-h4pp-46jw, MINI-qx28-7qjp-6x4c, MINI-r24j-gxp5-rxf7, MINI-r3rq-8hrw-4gjj, MINI-r7m8-pwg8-h234, MINI-rf78-vgfg-6mm6, MINI-rhm2-m3rj-rfvc, MINI-v2vx-j3qh-2fp8, MINI-v4gc-f9hc-vmv8, MINI-v6vf-c53v-jqjg, MINI-vqmr-42jm-6r87, MINI-vrfc-4g73-h369, MINI-w392-3hrq-2gv8, MINI-w4mm-qgj8-6h66, MINI-w9f9-c5pj-x7v7, MINI-wjxq-2gvj-jg8h, MINI-wqpf-q548-xwh4, MINI-x4wh-9rx6-3rg6, MINI-x5j9-8422-599x, MINI-xpmr-2245-4fj2, UBUNTU-CVE-2026-49835 ## What is CVE-2026-49835? CVE-2026-49835 is a medium-severity denial of service vulnerability in sigstore timestamp-authority, published on 17 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### 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/ or random HTTP methods and create unbounded permanent time-series entries that exhaust memory. This issue is fixed in version 2.1.0. Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling) ## Which versions are affected by CVE-2026-49835? 6 open source packages ship an affected version, including github.com/sigstore/timestamp-authority and github.com/sigstore/timestamp-authority/v2. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/sigstore/timestamp-authority` | Go | All versions | None | | `github.com/sigstore/timestamp-authority` | Go | All versions to 1.2.9 | None | | `github.com/sigstore/timestamp-authority` | Go | All versions to 1.2.9 | None | | `github.com/sigstore/timestamp-authority/v2` | Go | All versions | 2.1.0 | | `github.com/sigstore/timestamp-authority/v2` | Go | All versions | 2.1.0 | | `github.com/sigstore/timestamp-authority/v2` | Go | All versions | 2.1.0 | Products: Linuxfoundation Sigstore Timestamp Authority. ## How do I fix CVE-2026-49835? Upgrade to a fixed version. ## Is CVE-2026-49835 being exploited? There is no known exploitation of CVE-2026-49835 in the wild and no public exploit code. ## Other vulnerabilities in sigstore timestamp-authority - [CVE-2025-66564](https://insights.sbomify.com/CVE-2025-66564/): Sigstore Timestamp Authority allocates excessive memory during request parsing (high 7.5) - [CVE-2026-39984](https://insights.sbomify.com/CVE-2026-39984/): Sigstore Timestamp Authority has Improper Certificate Validation in verifier (medium 5.5) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-49835 and fix it if it is affected. What it is: CVE-2026-49835 is a medium-severity denial of service vulnerability in sigstore timestamp-authority, published on 17 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-49835 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/sigstore/timestamp-authority (Go): affected all versions; no fix listed - github.com/sigstore/timestamp-authority (Go): affected all versions up to 1.2.9; no fix listed - github.com/sigstore/timestamp-authority (Go): affected all versions up to 1.2.9; no fix listed - github.com/sigstore/timestamp-authority/v2 (Go): affected all versions; fixed in 2.1.0 - github.com/sigstore/timestamp-authority/v2 (Go): affected all versions; fixed in 2.1.0 - github.com/sigstore/timestamp-authority/v2 (Go): affected all versions; fixed in 2.1.0 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-49835/ (Markdown: https://insights.sbomify.com/CVE-2026-49835/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-49835 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-49835 - OSV: https://osv.dev/vulnerability/CVE-2026-49835 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-49835/ Summaries are generated and may contain mistakes; the official description above is the record.