# cert-manager-controller DoS via Specially Crafted DNS Response Advisory record · `GHSA-gx3x-vq4p-mhhv` - **Identifiers:** `GHSA-gx3x-vq4p-mhhv` · `BIT-cert-manager-2026-25518` · `CVE-2026-25518` · `GO-2026-4399` - **State:** Confirmed - **Severity:** CVSS 5.9 Medium - **Critical:** No - **Weakness (CWE):** [CWE-129](https://cwe.mitre.org/data/definitions/129.html) · [CWE-704](https://cwe.mitre.org/data/definitions/704.html) - **Tags:** [CWE-129](https://agentprime.io/advisories/tag/cwe-129.md) · [CWE-704](https://agentprime.io/advisories/tag/cwe-704.md) - **Published:** 2 Feb 2026 - **Updated:** 10 Sept 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 2 Feb 2026, 22:11 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `github.com/cert-manager/cert-manager` (Go): affected `>=1.18.0, <1.18.5 || >=1.19.0, <1.19.3`; fixed in `1.18.5`, `1.19.3` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > cert-manager-controller versions 1.18.0 to before 1.18.5 and 1.19.0 to before 1.19.3 (Go module github.com/cert-manager/cert-manager) are vulnerable to a denial of service. An attacker who can intercept or modify DNS traffic from the controller pod, or who controls the authoritative DNS server for the domain being validated, can insert a crafted DNS cache entry that causes a panic when accessed, crashing the controller. Upgrade to cert-manager 1.18.5 or 1.19.3. Using DNS-over-HTTPS reduces the interception risk but does not stop a malicious authoritative DNS server. Written 1 Nov 2026. ## Not analysed yet We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check. ## Severity and exploitation - 5.9 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.0037, the 31st percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 31 Oct 2026, 14:14 UTC: First seen by agentprime - 31 Oct 2026, 14:14 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-gx3x-vq4p-mhhv) ## Sources - [GitHub Advisory Database: GHSA-gx3x-vq4p-mhhv](https://github.com/advisories/GHSA-gx3x-vq4p-mhhv) - [OSV: GHSA-gx3x-vq4p-mhhv](https://osv.dev/vulnerability/GHSA-gx3x-vq4p-mhhv) - - - - - - - - - - Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code. ## Check whether this affects you A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet. - With the agentprime MCP server (), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .