cert-manager: Direct ACME Challenge resources can bypass Issuer DNS01 solver policy and use ClusterIssuer DNS credentials

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.3 · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

EPSS

• CVE-2026-62290: 0.11% estimated exploitation activity in the next 30 days; percentile 1.36 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary `Challenge` resources under `acme.cert-manager.io` can be created directly by namespace users. On create, cert-manager performs no admission validation tying the Challenge to an `Order`, an owner reference, or an Issuer-selected solver. The ACME Challenge controller then reconciles the direct resource and uses `Challenge.spec.solver` as the DNS01 provider configuration. When the direct Challenge references a `ClusterIssuer`, cert-manager derives the DNS provider secret namespace and ambient-credential policy from the `ClusterIssuer` reference, but the DNS provider configuration itself is attacker-controlled through `Challenge.spec.solver`. This lets a namespace user bypass `Issuer`/`ClusterIssuer` solver selectors such as `dnsZones`, `dnsNames`, and `matchLabels`, and make the cert-manager controller use ClusterIssuer DNS credentials for attacker-selected provider settings and DNS names. In the acme-dns case, this becomes credential disclosure because the…

Published by the source

29 Oct 2026, 16:39 UTC

Last modified by the source

29 Oct 2026, 16:45 UTC

Source last checked

30 Oct 2026, 07:05 UTC

1. Revision 2 · amended · 30 Oct 2026

   Amended from osv record GHSA-8rvj-mm4h-c258

2. Revision 1 · created · 29 Oct 2026

   Published from ghsa record GHSA-8rvj-mm4h-c258

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# Patch Next advisory brief: CVE-2026-62290

Advisory: cert-manager: Direct ACME Challenge resources can bypass Issuer DNS01 solver policy and use ClusterIssuer DNS credentials
IDs: CVE-2026-62290, GHSA-8rvj-mm4h-c258
Record: https://patchnext.com/advisories/cve-2026-62290 (revision 2, source checked 30 Oct 2026, 07:05 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/cert-manager/cert-manager 1.20.3, 1.19.6. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/cert-manager/cert-manager: affected >= 1.18.0, < 1.19.6; >= 1.20.0-alpha.0, < 1.20.3; fixed in 1.20.3, 1.19.6

## Suggested inspection (read-only)
- Go github.com/cert-manager/cert-manager: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/cert-manager/cert-manager.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-8rvj-mm4h-c258 (GitHub-reviewed advisory GHSA-8rvj-mm4h-c258 lists affected ranges: Go github.com/cert-manager/cert-manager >=1.18.0 =1.20.0-alpha.0 <1.20.3)
- Verified: https://osv.dev/vulnerability/GHSA-8rvj-mm4h-c258 (OSV record GHSA-8rvj-mm4h-c258 lists affected ranges: Go github.com/cert-manager/cert-manager >=1.18.0 =1.20.0-alpha.0 <1.20.3 (fixed))

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