CVE Intelligence
High Info disclosure

CVE-2024-4540 — Keycloak: exposure of sensitive information in pushed authorization requests (par) kc_restart cookie

A flaw was found in Keycloak in OAuth 2.0 Pushed Authorization Requests (PAR). Client-provided parameters were found to be included in plain text in the KC_RESTART cookie returned by the authorization server's HTTP response to a `request_uri` authorization request, possibly leading to an information disclosure vulnerability.

Published Jun 3, 2024 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: redhat

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.6% (30-day exploitation probability)+7
  • Technical severity (high)+6
  • Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.55%
ahead of 45% of scored CVEs · Oct 14, 2026
Affects
Red Hat
Red Hat build of Keycloak 22 and 5 more
CVSS base
7.5
High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Red Hat Red Hat build of Keycloak 22, Red Hat Red Hat build of Keycloak 24, Red Hat Red Hat Single Sign-On 7.6 for RHEL 7…).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (info disclosure), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Red Hat Red Hat build of Keycloak 22 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat build of Keycloak 24 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Single Sign-On 7.6 for RHEL 7 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Single Sign-On 7.6 for RHEL 8 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Single Sign-On 7.6 for RHEL 9 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat RHEL-8 based Middleware Containers versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
7.5 CVSS 3.1 High 3.9 3.6 secalert@redhat.com via NIST National Vulnerability Database
7.5 CVSS 3.1 High — — redhat via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N (score shown at the top: secalert@redhat.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-312 · Cleartext Storage of Sensitive Information

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.55%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Look for anomalous data read/export volumes and access to sensitive records.
web/proxy/WAF logsnetwork IDS/IPSapplication logsauthentication logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · red hat/red hat build of keycloak 22, red hat/red hat build of keycloak 24, red hat/red hat single sign-on 7.6 for rhel
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • CVSS changed · 7.5
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Deferred
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • 2024
  • CVE published
    Jun 3, 2024 · redhat

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

11 on the record

Elsewhere on this site

Red Hat
every CVE for this vendor
Info disclosure
same class
CWE-312
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-15563 Wildfly-iiop-openjdk: missing authentication on eap's iiop nameservice leads to mitm or dos Aug 11, 2026
  • CVE-2026-7507 Org.keycloak/keycloak-services: session fixation in oidc login flow that can lead to account takeover May 19, 2026
  • CVE-2026-7307 Keycloak: keycloak: denial of service via specially crafted saml input May 19, 2026
  • CVE-2026-4634 Keycloak: keycloak: denial of service via excessive processing of openid connect scope parameters Apr 2, 2026
  • CVE-2026-5121 Libarchive: libarchive: arbitrary code execution via integer overflow in iso9660 image processing Mar 30, 2026
  • CVE-2026-4424 Libarchive: libarchive: information disclosure via heap out-of-bounds read in rar archive processing Mar 19, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2024-4540 is "Keycloak: exposure of sensitive information in pushed authorization requests (par) kc_restart cookie", rated High. It affects Red Hat build of Keycloak 22 (Red Hat); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.5 describes technical severity. EPSS 0.55% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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