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CVE-2025-12390: keycloak Session Fixation

CVSS: 6.0v3.1MediumDeferred
AliasesCGA-c84j-x8xw-83v6CGA-jrvw-p2c3-r7c3CGA-2cw8-p44g-xmjf
Published 28-10-2025Last modified 30-07-2026
Open JSON

Vulnerability summary

CVE-2025-12390 is a medium (CVSS 6.0) Session Fixation vulnerability in keycloak. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 2.9% of scored vulnerabilities.

Overall risk
24/100
0100
Low · default modelHow is this calculated?
CVSS score
6.0/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.14%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CGA-M6JM-QXW7-GC4W

Timeline

  1. 28-10-2025
    PublishedVulnerability first disclosed.
  2. 30-07-2026
    Last modifiedVulnerability information updated.

Description

A flaw was found in Keycloak. In Keycloak where a user can accidentally get access to another user's session if both use the same device and browser. This happens because Keycloak sometimes reuses session identifiers and doesn’t clean up properly during logout when browser cookies are missing. As a result, one user may receive tokens that belong to another user.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.14%

Chance of exploitation in the next 30 days

Percentile

3%

Versus all other CVEs

30-day change

+0.01 pp

From 0.13% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.14%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard7 products
  • keycloak-26.2< 26.2.5-r6
  • keycloak-26.2-iamguarded-compat< 26.2.5-r6
  • keycloak-26.3-iamguarded-compat< 26.3.5-r3
  • keycloak-26.4< 26.4.4-r0
  • keycloak-fips-26.2-iamguarded-fips< 26.2.5-r8
Keycloak1 product
Org.keycloak1 product
  • keycloak-services< 26.0.0
Wolfi1 product
  • keycloak-26.4< 26.4.4-r0

4 vendors · 10 products

References

18 links
Show all 18 references