CVE-2026-25518: cert-manager adds certificates and certificate issuers as resource types in Kubernetes clusters, and simplifie

Routine

MEDIUM 5.9REMOTEWATCHLISTUPGRADE

CVE-2026-25518 is a medium-severity flaw (CVSS 5.9) affecting cert-manager. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 w

Why this priority

Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 68%)
CISA exploited list	No
Weakness	CWE-129, CWE-704
Published	2026-02-04
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: cert-manager

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-02-04 22:15 UTCPublished CVE record published
2026-06-17 10:24 UTCUpdated Record last modified

cert-manager cert-manager UPGRADE

Affected: >= 1.18.0 and < 1.18.5 · >= 1.19.0 and < 1.19.3

Fixed in: 1.18.5, 1.19.3

Safe to downgrade to: a release before 1.18.0

1. Check installed version

apt-cache policy cert-manager || rpm -q cert-manager || cert-manager --version

2. UPGRADE to 1.18.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade cert-manager

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade cert-manager

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.18.0 (Debian / Ubuntu)

apt-cache madison cert-manager sudo apt install cert-manager=<VERSION_BEFORE_1.18.0> sudo apt-mark hold cert-manager

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list cert-manager sudo dnf downgrade cert-manager-<VERSION_BEFORE_1.18.0> sudo dnf versionlock add cert-manager

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-25518?

cert-manager: upgrade to 1.18.5, 1.19.3. Exact commands for each OS are on this page.

Is CVE-2026-25518 being exploited?

CVE-2026-25518 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-25518 affect?

CVE-2026-25518 affects cert-manager. Severity is medium (CVSS 5.9). 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 bef

How urgent is CVE-2026-25518?

Priority 39/100. Remotely exploitable, no login, no user action; On your watchlist

Software pages

Kubernetes vulnerabilities

Related CVEs

CVE-2026-62290 HIGH 7.3 UPGRADE cert-manager adds certificates and certificate issuers as resource types in Kubernetes clusters, and simplifie
CVE-2024-36537 HIGH 7.2 DOWNGRADE Insecure permissions in cert-manager v1.14.4 allows attackers to access sensitive data and escalate privileges

References

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