fix(deps): update module github.com/cert-manager/cert-manager to v1.19.3 [security]

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
github.com/cert-manager/cert-manager	v1.19.2 → v1.19.3

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cert-manager-controller DoS via Specially Crafted DNS Response

CVE-2026-25518 / GHSA-gx3x-vq4p-mhhv

More information

Details

Impact

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.

Patches

The vulnerability was introduced in cert-manager v1.18.0 and has been patched in cert-manager v1.19.3 and v1.18.5, which are the supported minor releases at the time of publishing.

cert-manager versions prior to v1.18.0 are unaffected.

Workarounds

• Using DNS-over-HTTPS reduces the risk of DNS traffic being intercepted and modified.
  • Note that DNS-over-HTTPS does not prevent the risk of an attacker-controlled authoritative DNS server.

Resources

• Fix for cert-manager 1.18: https://github.com/cert-manager/cert-manager/pull/8467
• Fix for cert-manager 1.19: https://github.com/cert-manager/cert-manager/pull/8468
• Fix for master branch: https://github.com/cert-manager/cert-manager/pull/8469

Credits

Huge thanks to Oleh Konko (@​1seal) for reporting the issue, providing a detailed PoC and an initial patch!

Severity

• CVSS Score: 5.9 / 10 (Medium)
• Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

References

• https://github.com/cert-manager/cert-manager/security/advisories/GHSA-gx3x-vq4p-mhhv
• https://github.com/cert-manager/cert-manager/pull/8467
• https://github.com/cert-manager/cert-manager/pull/8468
• https://github.com/cert-manager/cert-manager/pull/8469
• https://github.com/cert-manager/cert-manager/commit/409fc24e539711a07aae45ed45abbe03dfdad2cc
• https://github.com/cert-manager/cert-manager/commit/9a73a0b3853035827edd37ac463e4803ba10327d
• https://github.com/cert-manager/cert-manager/commit/d4faed26ae12115cceb807cdc12507ebc28980e2
• https://nvd.nist.gov/vuln/detail/CVE-2026-25518
• https://pkg.go.dev/vuln/GO-2026-4399
• https://github.com/advisories/GHSA-gx3x-vq4p-mhhv

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

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Release Notes

cert-manager/cert-manager (github.com/cert-manager/cert-manager)

v1.19.3

Compare Source

cert-manager is the easiest way to automatically manage certificates in Kubernetes and OpenShift clusters.

This release contains three bug fixes, including a fix for the MODERATE severity DoS issue in GHSA-gx3x-vq4p-mhhv. All users should upgrade to the latest release.

Changes by Kind

Bug or Regression

• Fixed an infinite re-issuance loop that could occur when an issuer returns a certificate with a public key that doesn't match the CSR. The issuing controller now validates the certificate before storing it and fails with backoff on mismatch. (#​8415, @​cert-manager-bot)
• Fixed an issue where HTTP-01 challenges failed when the Host header contained an IPv6 address. This means that users can now issue IP address certificates for IPv6 address subjects. (#​8436, @​cert-manager-bot)
• Security (MODERATE): Fix a potential panic in the cert-manager controller when a DNS response in an unexpected order was cached. If an attacker was able to modify DNS responses (or if they controlled the DNS server) it was possible to cause denial of service for the cert-manager controller. (#​8468, @​SgtCoDFish)

Other (Cleanup or Flake)

• Bump go to 1.25.6 (#​8459, @​SgtCoDFish)

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