What is CVE-2026-18963?

CVE-2026-18963 is Keycloak-services: keycloak-services: unauthenticated account takeover via reset-credentials flow bypass. The supplied enrichment data classifies it as Unclassified mapped to CWE-640 CWE-640.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Exploitation is reported, but no independent confirmation is available in the sources we have. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-18963 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

17 public PoC repositories reported; 2 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-18963 using CVSS 9.1, EPSS 3%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

criticalpublic exploit

CVE-2026-18963

CVE-2026-18963 — Keycloak-services: keycloak-services: unauthenticated account takeover via reset-credentials flow bypass

A flaw was found in the reset-credentials flow of the keycloak-services component, which is the core engine for identity and access management in Red Hat Build of Keycloak. The issue allows an unauthenticated attacker to force the password reset process for any user without needing to click the required email verification link. This can result in the attacker gaining full control over target user accounts by directly setting new credentials.

Published Aug 18, 2026Updated Aug 20, 2026Sources: NVD, Red Hat (CNA), GitHub, Red Hat (VEX), SOCRadar CTI

Triage

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

Exploitation

Reported

not confirmed by CISA

EPSS

ahead of 85% of scored CVEs

Affects

Red Hat

13 products listed

CVSS base

9.1

critical

CISA SSVC assessment

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

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

Yes

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade Red Hat build of Keycloak 26.4 to a fixed release (26.4.15-1). Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

Red Hat VEX · CVE-2026-18963

fixed20affected0not affected2

vendor_fix: Before applying the update, back up your existing installation, including all applications, configuration files, databases and database settings, and so on.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
Red Hat	Red Hat build of Keycloak 26.4	26.4.15-1	Patched
Red Hat	Red Hat build of Keycloak 26.4	26.4-23	Patched
Red Hat	Red Hat build of Keycloak 26.4	26.4-23	Patched
Red Hat	Red Hat build of Keycloak 26.4.15	—	Patched
Red Hat	Red Hat build of Keycloak 26.4.15	—	Patched
Red Hat	Red Hat build of Keycloak 26.6	26.6.6-1	Patched
Red Hat	Red Hat build of Keycloak 26.6	26.6-12	Patched
Red Hat	Red Hat build of Keycloak 26.6	26.6-12	Patched
Red Hat	Red Hat build of Keycloak 26.6.6	—	Patched
Red Hat	Red Hat build of Keycloak 26.6.6	—	Patched
Red Hat	Red Hat build of Keycloak 26.6.6	—	Patched
Red Hat	Red Hat JBoss Enterprise Application Platform Expansion Pack	—	Patched

Attack characteristics

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

Availability

None

Confidentiality

High

Integrity

High

Scope

Unchanged

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

None

Every base score collected

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

Score	Version	Severity	Expl.	Impact	Source
9.1	CVSS 3.1	critical	3.9	5.2	Red Hat (CNA), Red Hat (VEX)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-640 · Weak Password Recovery Mechanism for Forgotten Password

Gain Privileges or Assume Identity
DoS: Resource Consumption (Other)
Other

Mitigation: Make sure that all input supplied by the user to the password recovery mechanism is thoroughly filtered and validated.

Weakness & attack patterns

CWE-640

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-50 · Password Recovery Exploitation

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

2 of the 5 sampled are weaponized

Exploit entries

Exploit-DB and CTI exploit indexes

Social mentions

Posts naming this CVE. Attention, not evidence of exploitation — it spikes on disclosure and decays whether or not anything is exploited.

35 more posts on this CVEShowing 5 of 40 · Who is discussing this CVE, and how loudlyUnlock free

Detection

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

Prioritize edge telemetry for network-reachable Red Hat build of Keycloak 26.4, Red Hat build of Keycloak 26.4.15, Red Hat build of Keycloak 26.6, Red Hat build of Keycloak 26.6.6, Red Hat JBoss Enterprise Application Platform Expansion Pack, Red Hat Single Sign-On 7.
Monitor for scanner or exploit-pattern traffic after 17 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Cve is exploited BlackHatExploitation/Exploit-For-CVE-2026-18963
Aug 27, 2026 · SOCRadar CTI
Cve is exploited gman0x00/keycloak-CVE-2026-18963
Aug 26, 2026 · SOCRadar CTI
Cve is exploited prot0tw/Keycloak_CVE-2026-18963_PoC
Aug 25, 2026 · SOCRadar CTI
Cve is exploited Snizi/CVE-2026-18963-Exploit
Aug 24, 2026 · SOCRadar CTI
Cve is exploited T0w0T/POC-CVE-2026-18963
Aug 24, 2026 · SOCRadar CTI
Cve is exploited kyos-public/keycloak-cve-2026-18963-hunt
Aug 22, 2026 · SOCRadar CTI
Added · CVSS 3.1 9.1 (AV:N)
Aug 20, 2026 · NVD
Initial · CVE published
Aug 18, 2026 · NVD
Reported · Made public.
Aug 17, 2026 · Red Hat
Reported to Red Hat.
Jul 31, 2026 · Red Hat

Source activity

Readings a source repeats on a schedule, counted rather than listed.

10×Github ReposAug 20, 2026 – Aug 27, 2026 · SOCRadar CTI
8×TweetsAug 21, 2026 – Aug 28, 2026 · SOCRadar CTI
7×SvrsAug 22, 2026 – Aug 29, 2026 · SOCRadar CTI
5×CVE modified by MITRE: CVSS metrics updated.Aug 18, 2026 – Aug 20, 2026 · SOCRadar CTI
3×TelegramAug 20, 2026 – Aug 26, 2026 · SOCRadar CTI
1×CVE appeared in the Cve Trends.Aug 24, 2026 · SOCRadar CTI

References

9 on the record

access.redhat.com/errata/RHSA-2026:56519
Vendor Advisory, Mitre, NIST
access.redhat.com/errata/RHSA-2026:56520
Vendor Advisory, Mitre, NIST
access.redhat.com/errata/RHSA-2026:56523
Vendor Advisory, Mitre, NIST
access.redhat.com/errata/RHSA-2026:56524
Vendor Advisory, Mitre, NIST
access.redhat.com/security/cve/CVE-2026-18963
Vendor Advisory, NIST
bugzilla.redhat.com/show_bug.cgi?id=2511595
Vendor Advisory, Mitre, NIST
www.cve.org/CVERecord?id=CVE-2026-18963
Vendor Advisory
nvd.nist.gov/vuln/detail/CVE-2026-18963
NVD

Coverage

5 stories from the feeds we poll

Elsewhere on this site

Red Hatevery CVE for this vendor
Unclassifiedsame class
CWE-640other pages naming this weakness

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 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 record1

What should defenders know first?

CVE-2026-18963 is Keycloak-services: keycloak-services: unauthenticated account takeover via reset-credentials flow bypass, a critical vulnerability affecting Red Hat build of Keycloak 26.4, Red Hat build of Keycloak 26.4.15, Red Hat build of Keycloak 26.6, Red Hat build of Keycloak 26.6.6, Red Hat JBoss Enterprise Application Platform Expansion Pack, Red Hat Single Sign-On 7 from Red Hat. The current evidence does not list it in CISA KEV, and the exploit status is: Exploitation is reported, but no independent confirmation is available in the sources we have. Public exploit evidence is: 17 public PoC repositories reported; 2 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 9.1 describes technical severity, while EPSS 3% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.