CVE-2017-12159: It was found that the cookie used for CSRF prevention in Keycloak was not unique to each session

This month

HIGH 7.5REMOTEWATCHLISTDOWNGRADEMITIGATE

CVE-2017-12159 is a high-severity flaw (CVSS 7.5) affecting single sign on, keycloak. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

It was found that the cookie used for CSRF prevention in Keycloak was not unique to each session. An attacker could use this flaw to gain access to an authenticated user session, leading to possible information disclosure or further attacks.

Why this priority

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

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.7% (top 14%)
CISA exploited list	No
Weakness	CWE-613
Published	2017-10-26
Last modified	2026-06-17

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

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

Am I affected?

Timeline

2017-10-26 17:29 UTCPublished CVE record published
2026-06-17 01:02 UTCUpdated Record last modified

redhat single sign on DOWNGRADE

Affected: 7.0 · 7.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0

1. Check installed version

apt-cache policy single-sign-on || rpm -q single-sign-on || single-sign-on --version

2. No fixed release: DOWNGRADE to a release before 7.0 (Debian / Ubuntu)

apt-cache madison single-sign-on sudo apt install single-sign-on=<VERSION_BEFORE_7.0> sudo apt-mark hold single-sign-on

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list single-sign-on sudo dnf downgrade single-sign-on-<VERSION_BEFORE_7.0> sudo dnf versionlock add single-sign-on

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.

keycloak keycloak MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

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

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

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-2017-12159?

single sign on: downgrade or apply the listed mitigation; keycloak: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2017-12159 being exploited?

CVE-2017-12159 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-2017-12159 affect?

CVE-2017-12159 affects single sign on, keycloak. Severity is high (CVSS 7.5). It was found that the cookie used for CSRF prevention in Keycloak was not unique to each session. An attacker could use this flaw to gain access to an authenticated user session, leading to possible information disclosure or further attacks

How urgent is CVE-2017-12159?

Priority 58/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Keycloak vulnerabilities

Related CVEs

CVE-2017-2585 MEDIUM 5.9 UPGRADE DOWNGRADE Red Hat Keycloak before version 2.5.1 has an implementation of HMAC verification for JWS tokens that uses a me
CVE-2017-12158 MEDIUM 5.4 DOWNGRADE MITIGATE It was found that Keycloak would accept a HOST header URL in the admin console and use it to determine web res
CVE-2016-8629 MEDIUM 6.5 UPGRADE DOWNGRADE Red Hat Keycloak before version 2.4.0 did not correctly check permissions when handling service account user d

References

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