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@renovate renovate bot commented Feb 3, 2026

This PR contains the following updates:

Package Change Age Adoption Passing Confidence
github.com/cert-manager/cert-manager v1.19.2v1.19.3 age adoption passing confidence

cert-manager-controller DoS via Specially Crafted DNS Response

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
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

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


Release Notes

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

v1.19.3

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@fwiesel
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fwiesel commented Feb 3, 2026

We are not really affected by it, but it is easier to merge it than to discuss it away.

@renovate renovate bot force-pushed the renovate/go-github.com-cert-manager-cert-manager-vulnerability branch from cb080a7 to ea7f951 Compare February 3, 2026 10:20
@fwiesel fwiesel merged commit 9e44049 into main Feb 3, 2026
6 checks passed
@fwiesel fwiesel deleted the renovate/go-github.com-cert-manager-cert-manager-vulnerability branch February 3, 2026 10:53
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4 participants