CVE-2026-7307: A flaw was found in Keycloak

This month

HIGH 7.5REMOTEWATCHLISTUPGRADE

CVE-2026-7307 is a high-severity flaw (CVSS 7.5) affecting build of keycloak. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A flaw was found in Keycloak. A remote, unauthenticated attacker can send a specially crafted XML input to the Security Assertion Markup Language (SAML) endpoint. This malicious input can cause high CPU usage and worker thread starvation, leading to a Denial of Service (DoS) where the server becomes unavailable.

Why this priority

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

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 41%)
CISA exploited list	No
Weakness	CWE-1286
Published	2026-05-19
Last modified	2026-10-26

Publisher (CNA): Red Hat, Inc. · Vendor: redhat

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-19 12:16 UTCPublished CVE record published
2026-10-26 13:10 UTCUpdated Record last modified

redhat build of keycloak UPGRADE

Affected: >= 26.4 and < 26.4.12

Fixed in: 26.4.12

Safe to downgrade to: a release before 26.4

1. Check installed version

apt-cache policy build-of-keycloak || rpm -q build-of-keycloak || build-of-keycloak --version

2. UPGRADE to 26.4.12 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade build-of-keycloak

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade build-of-keycloak

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 26.4 (Debian / Ubuntu)

apt-cache madison build-of-keycloak sudo apt install build-of-keycloak=<VERSION_BEFORE_26.4> sudo apt-mark hold build-of-keycloak

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

dnf --showduplicates list build-of-keycloak sudo dnf downgrade build-of-keycloak-<VERSION_BEFORE_26.4> sudo dnf versionlock add build-of-keycloak

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-2026-7307?

build of keycloak: upgrade to 26.4.12. Exact commands for each OS are on this page.

Is CVE-2026-7307 being exploited?

CVE-2026-7307 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-2026-7307 affect?

CVE-2026-7307 affects build of keycloak. Severity is high (CVSS 7.5). A flaw was found in Keycloak. A remote, unauthenticated attacker can send a specially crafted XML input to the Security Assertion Markup Language (SAML) endpoint. This malicious input can cause high CPU usage and worker thread starvation, l

How urgent is CVE-2026-7307?

Priority 51/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Keycloak vulnerabilities

Related CVEs

CVE-2026-7507 HIGH 7.5 UPGRADE A session fixation vulnerability was found in Keycloak's login-actions endpoints
CVE-2026-7504 HIGH 8.1 UPGRADE A flaw was found in Keycloak's URL validation logic during redirect operations
CVE-2026-7571 HIGH 7.1 UPGRADE A flaw was found in Keycloak
CVE-2026-37982 MEDIUM 6.8 UPGRADE A flaw was found in Keycloak
CVE-2026-37979 MEDIUM 6.5 UPGRADE A flaw was found in Keycloak

References

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