CVE-2026-25518
An attacker who can intercept and modify DNS traffic from the cert-manager-controller pod can insert a crafted entry into cert-manager's DNS cache.
Does this matter?
Lower severity and a low EPSS score (0.36%). Track it; it rarely justifies an emergency change on its own.
Description
cert-manager adds certificates and certificate issuers as resource types in Kubernetes clusters, and simplifies the process of obtaining, renewing and using those certificates. In versions from 1.18.0 to before 1.18.5 and from 1.19.0 to before 1.19.3, the cert-manager-controller performs DNS lookups during ACME DNS-01 processing (for zone discovery and propagation self-checks). By default, these lookups use standard unencrypted DNS. An attacker who can intercept and modify DNS traffic from the cert-manager-controller pod can insert a crafted entry into cert-manager's DNS cache. Accessing this entry will trigger a panic, resulting in denial‑of‑service (DoS) of the cert-manager controller. The issue can also be exploited if the authoritative DNS server for the domain being validated is controlled by a malicious actor. This issue has been patched in versions 1.18.5 and 1.19.3.
- CVSS 3.1
- 5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.36% probability · 30th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-129, CWE-704
- Affected
- cert-manager/cert-manager
- Source
- security-advisories@github.com
References
- https://github.com/cert-manager/cert-manager/commit/409fc24e539711a07aae45ed45abbe03dfdad2ccPatch
- https://github.com/cert-manager/cert-manager/commit/9a73a0b3853035827edd37ac463e4803ba10327dPatch
- https://github.com/cert-manager/cert-manager/commit/d4faed26ae12115cceb807cdc12507ebc28980e2Patch
- https://github.com/cert-manager/cert-manager/pull/8467Issue Tracking, Patch
- https://github.com/cert-manager/cert-manager/pull/8468Issue Tracking, Patch
- https://github.com/cert-manager/cert-manager/pull/8469Issue Tracking, Patch
- https://github.com/cert-manager/cert-manager/security/advisories/GHSA-gx3x-vq4p-mhhvMitigation, Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.