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TI-2026-14983 Aliases CVE-2026-18212GHSA-wgrv-cjmx-4vfw

Keycloak-services: keycloak-services: saml redirect deflate helpers leak native zlib state

Priority MEDIUM 40CWE-401Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 4 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-401.

Summary

A flaw was found in the SAML Redirect Binding implementation of Keycloak, an open-source identity and access management solution. The issue occurs because the custom DEFLATE compression and decompression helpers fail to release native zlib memory after use. An unauthenticated attacker can exploit this by sending repeated malformed SAML requests, leading to native memory exhaustion and a denial of service.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00704 53rd percentileScored 2026-11-07
Fix Partial Red Hat: 4 advisoriesRed Hat: 4 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Red HatRed Hat build of Keycloak 26.4—26.4.16-2Patch availableCNA
Red HatRed Hat build of Keycloak 26.4—26.4-26Patch availableCNA
Red HatRed Hat build of Keycloak 26.4—26.4-26Patch availableCNA
Red HatRed Hat build of Keycloak 26.4.16——Not affectedCNA
Red HatRed Hat build of Keycloak 26.4.16——Not affectedCNA
Red HatRed Hat build of Keycloak 26.6—26.6.7-3Patch availableCNA
Red HatRed Hat build of Keycloak 26.6—26.6-20Patch availableCNA
Red HatRed Hat build of Keycloak 26.6—26.6-20Patch availableCNA
Red HatRed Hat build of Keycloak 26.6.7——Not affectedCNA
Red HatRed Hat build of Keycloak 26.6.7——Not affectedCNA
Red HatRed Hat build of Keycloak 26.6.7——Not affectedCNA
Red HatRed Hat Data Grid 8——No fix listedCNA
Red HatRed Hat JBoss Enterprise Application Platform Expansion Pack——Not affectedCNA
Red HatRed Hat Single Sign-On 7——No fix listedCNA
  • Red Hat build of Keycloak 26.4 VendorRed Hat Affected — Fixed in 26.4.16-2 Patch available CNA
  • Red Hat build of Keycloak 26.4 VendorRed Hat Affected — Fixed in 26.4-26 Patch available CNA
  • Red Hat build of Keycloak 26.4 VendorRed Hat Affected — Fixed in 26.4-26 Patch available CNA
  • Red Hat build of Keycloak 26.4.16 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat build of Keycloak 26.4.16 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6.7-3 Patch available CNA
  • Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6-20 Patch available CNA
  • Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6-20 Patch available CNA
  • Red Hat build of Keycloak 26.6.7 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat build of Keycloak 26.6.7 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat build of Keycloak 26.6.7 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat Data Grid 8 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat JBoss Enterprise Application Platform Expansion Pack VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat Single Sign-On 7 VendorRed Hat Affected — Fixed in — No fix listed CNA

CPE names CNA · 5

CPEVersionsRoleVendor
cpe:/a:redhat:build_keycloak:26.4::el926.4—Red Hat
cpe:/a:redhat:build_keycloak:26.6::el926.6—Red Hat
cpe:/a:redhat:jboss_data_grid:88—Red Hat
cpe:/a:redhat:jbosseapxp——Red Hat
cpe:/a:redhat:red_hat_single_sign_on:77—Red Hat
  • cpe:/a:redhat:build_keycloak:26.4::el9 Versions 26.4 — ·Red Hat
  • cpe:/a:redhat:build_keycloak:26.6::el9 Versions 26.6 — ·Red Hat
  • cpe:/a:redhat:jboss_data_grid:8 Versions 8 — ·Red Hat
  • cpe:/a:redhat:jbosseapxp Versions — — ·Red Hat
  • cpe:/a:redhat:red_hat_single_sign_on:7 Versions 7 — ·Red Hat

Remediation

Red Hat 4 advisories

  • RHSA-2026:68276 Released 2026-09-16 · Red Hat rating Important
    Red Hat build of Keycloak 26.4.16 Images Security Update
    • Red Hat build of Keycloak 26.4 rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator
  • RHSA-2026:68277 Released 2026-09-16 · Red Hat rating Important
    Red Hat build of Keycloak 26.6.7 Images Security Update
    • Red Hat build of Keycloak 26.6 rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator
  • RHSA-2026:68280 Released 2026-09-16 · Red Hat rating Important
    Red Hat build of Keycloak 26.4.16 Security Update
    • Red Hat build of Keycloak 26.4.16
Show 1 more Red Hat advisories
  • RHSA-2026:68278 Released 2026-09-16 · Red Hat rating Important
    Red Hat build of Keycloak 26.6.7 Security Update
    • Red Hat build of Keycloak 26.6.7

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Data Grid 8AffectedNo fix planned: Will not fix
Red Hat Single Sign-On 7AffectedNo fix planned: Will not fix
Red Hat build of Keycloak 26.4Fixed RHSA-2026:68276
Red Hat build of Keycloak 26.4.16Fixed RHSA-2026:68280
Red Hat build of Keycloak 26.6Fixed RHSA-2026:68277
Red Hat build of Keycloak 26.6.7Fixed RHSA-2026:68278
Not affected: 1 product
  • Red Hat JBoss Enterprise Application Platform Expansion Pack

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-18212
  2. 2026-10-03 Alias added: GHSA-wgrv-cjmx-4vfw
  3. 2026-10-08 Affected versions changed · Red Hat
  4. 2026-10-16 Affected versions changed · Red Hat
  5. 2026-10-25 EPSS moved to the 50th–90th percentile
  6. 2026-10-25 Priority changed: LOW → MEDIUM

References

Advisory 4

Other 2

  • TI-2019-15875 Protection mechanism failure in Jenkins Pipeline: Groovy Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-15874 Protection mechanism failure in Jenkins Script Security Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
  • TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
  • TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
See all 7413 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences