SecurityIndependently confirmed3 publishers3 min readPublished Updated
Keycloak's forgotten-password flow hands over admin accounts, and the fix is already tagged
CVE-2026-18963 lets an unauthenticated request skip the emailed reset token entirely. Upstream 26.7.2 and four Red Hat errata are out, and the stopgap has to be set realm by realm.
The Watch · Security desk

What happened
- Red Hat and the Keycloak project patched CVE-2026-18963, rated 9.1, which lets an unauthenticated remote attacker force a password reset on any account.
- Exploitation yields a complete takeover of any account, administrative ones included.
- Upstream is fixed in 26.7.2, released August 19, 2026; Red Hat build of Keycloak customers take the 26.4.15 and 26.6.6 updates.
- For anyone who cannot update, Red Hat's stopgap is switching off Forgot password in every realm.
Why it matters
- exposure A broker admin account is not a local asset, and on Mongin's reading of Keycloak boundary failures the reachable set becomes every application that trusts the tokens it issues.
- cost The stopgap is paid for in help-desk resets across every realm, and completeness is on you, so a large multi-realm estate saves little by choosing it over the upgrade.
- constraint With no version ranges in the machine-readable advisory, dependency scanners have nothing to match on, and confirming exposure falls back on a person reading Red Hat's errata.
- decision Nobody has published which reset-credentials configurations are actually exploitable, which removes the usual grounds for deferring on the argument that your realm setup is unusual.
The emailed action token is the whole security model of a forgotten-password flow. It is the single artifact proving that whoever is choosing the new password controls the mailbox attached to the account. Red Hat's advisory places the root cause in improper state validation inside the reset-credentials flow, and its bug report describes a crafted request that moves the authentication session straight to the password update phase, with the token that Keycloak normally mails never required [3]. The check is not weakened, it is bypassed.
Since the takeover extends to administrative accounts [4], the interesting boundary is not the Keycloak console. Enzo Mongin of Escape, writing in July about a separate Keycloak access-control flaw, described an attacker who crosses one of the server's boundaries as not stopping there: "they get into everything sitting behind it" [14].
Red Hat issued four errata on August 18, 2026, covering the standalone server packages and the container images for two RHBK streams [10], a day ahead of the upstream 26.7.2 tag [18]. The version detail is where the work is: the 26.4 stream is clear from operator bundle 26.4.15-1 and the rhbk/keycloak-rhel9 images at 26.4-23, the 26.6 stream from operator bundle 26.6.6-1 and containers at 26.6-12 [11]. That specificity exists almost entirely inside Red Hat's own publications. The GitHub advisory lists both affected and patched versions as unknown, and the CVE record carries only Red Hat product references [7]. The product list has also moved underfoot: the initial record marked Red Hat Single Sign-On 7 unaffected and the JBoss EAP Expansion Pack affected, a later revision narrowed the list, and NVD truncates its display, so neither status is established [8].
Univention's position, published August 20, is that Nubus is unaffected because the forgotten-password feature is not activated in its Keycloak deployments [15]. That is consistent with the toggle being the determining condition, but no published source says whether every realm with the feature enabled is exploitable or only certain reset-credentials flow configurations [20]. Univention's answer rests on the feature being off, not on the flow being safe.
Look at the tempo around this. Keycloak 26.7.1, on August 5, carried twelve CVE fixes, among them a SAML identity-provider-initiated broker login that bypassed a link-only restriction and a default dynamic client registration policy that allowed role forgery via user property mappers [13]. 26.7.2 carried eight more, including a predictable account-linking hash that enables account takeover through a malicious OIDC client [9]. Twenty fixes in two releases fourteen days apart [16][17] is an argument for tracking versions rather than adjudicating flaws one at a time, particularly since no source addresses whether this fix closes the issue completely [19]. As of August 24 nobody had reported exploitation and no verified public exploit had been located [12], which is the calm part of the window, not evidence that the window is wide.
What to watch
- A verified public proof-of-concept or a first in-the-wild report, which converts a planned maintenance window into incident handling.
- A further CVE against the same reset-credentials flow, which would suggest the August fix was partial rather than complete.
- A settled product list in the CVE record, particularly whether JBoss EAP Expansion Pack builds are in scope.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence78
- Adoption
- Insufficient
- Hype gap+8
- Incentives30
- Confidence72
Perspective Coverage
4 publishers- Builder
- Builder 43%
- Operator
- Operator 51%
- Investor
- Investor 6%
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
Red Hat and the Keycloak project released patches for CVE-2026-18963, a critical flaw in the identity and access management server that could allow an unauthenticated remote attacker to take over any user account by forcing a password reset. Red Hat, acting as CNA, rated it 9.1 on CVSS and classified it as CWE-640, weak password recovery mechanism for a forgotten password.
- [2]
Red Hat assessed the severity as Critical because an unauthenticated remote attacker can exploit the flaw without any user interaction.
- [3]
Red Hat's CVE advisory gives the root cause as "improper state validation within the reset-credentials authentication flow"; per the Red Hat bug report, an attacker sends a specially crafted request to the reset-credentials endpoint, the authentication session transitions directly to the password update phase, and the action token Keycloak normally sends via email is never required.
- [4]
Successful exploitation results in a complete account takeover of any user, "including administrative accounts," by resetting their password.
- [5]
Upstream Keycloak users are advised to update to 26.7.2, released August 19, 2026; Red Hat build of Keycloak customers should apply the updates shipped for 26.4.15 and 26.6.6.
- [6]
For deployments that cannot update immediately, Red Hat published a temporary mitigation: turn off the "Forgot password" functionality across all realms, found in the RHBK administration console under Realm settings, then Login, then Forgot password. Red Hat said the setting must be applied to every realm and that customers should upgrade to a fixed version as soon as possible.
- [7]
The GitHub advisory for the flaw lists both the affected and the patched versions as unknown, and the CVE record carries only Red Hat product references.
- [8]
The initial CVE record listed Red Hat Single Sign-On 7 as unaffected and the Red Hat JBoss Enterprise Application Platform Expansion Pack as affected; a later revision narrowed the product list and NVD's display truncates it, so the current status of both is not established.
- [9]
CVE-2026-18963 was one of eight CVE identifiers listed as fixed in the Keycloak 26.7.2 release notes; the same release addressed CVE-2026-15571, a predictable account-linking hash that enables account takeover through a malicious OpenID Connect client.
- [10]
Red Hat issued four errata on August 18, 2026 (RHSA-2026:56519, RHSA-2026:56520, RHSA-2026:56523 and RHSA-2026:56524), covering the standalone server packages and the container images for two RHBK streams.
- [11]
Red Hat build of Keycloak 26.4 is unaffected from operator bundle 26.4.15-1 and from the rhbk/keycloak-rhel9 and rhbk/keycloak-rhel9-operator images 26.4-23; 26.6 is unaffected from operator bundle 26.6.6-1 and from the keycloak-rhel9 and operator containers 26.6-12.
- [12]
There is no evidence the flaw has been exploited, and no verified public exploit had been located as of August 24, 2026.
- [13]
On August 5, 2026, Keycloak 26.7.1 shipped fixes for twelve CVEs, including a SAML identity-provider-initiated broker login that bypassed a link-only restriction and a default dynamic client registration policy that allowed role forgery via user property mappers.
- [14]
Escape researcher Enzo Mongin, writing about a separate Keycloak access-control flaw he disclosed in July, said an attacker who crosses one of the server's boundaries does not stop at Keycloak, and that "they get into everything sitting behind it."
- [15]
Univention said in a post published August 20 that "Nubus is not affected by this issue" because the forgotten-password feature is not activated in its Keycloak deployments.
- [16]
Keycloak 26.7.1 and 26.7.2 together carried twenty CVE fixes.
- [17]
The two releases were fourteen days apart: 26.7.1 on August 5, 2026 and 26.7.2 on August 19, 2026.
- [18]
Red Hat's four errata, dated August 18, 2026, preceded the upstream 26.7.2 release of August 19, 2026 by one day.
- [19]
No source addresses whether the fix fully resolves the flaw.
- [20]
Whether every realm with the forgotten-password feature enabled is exploitable, or only certain reset-credentials flow configurations, is not stated by any of the published sources.
Sources
3 independent publishers whose own reporting we read for this story.
- CVE-2026-18963 - Red Hat Customer Portal
access.redhat.com
1 article · August 25, 2026
- github.comCVE-2026-18963 Unauthenticated account takeover via reset-credentials flow bypass · Issue #51833 · keycloak/keycloak · GitHub
1 article · August 25, 2026
- Keycloak 26.7.2 released - Keycloak
keycloak.org
1 article · August 25, 2026
- thehackernews.comCritical Keycloak Password Reset Flaw Could Let Unauthenticated Attackers Take Over Any Account
2 articles · August 24, 2026
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Topics
- Password recovery securityFollow
- Identity and Access ManagementFollow
- Account TakeoverFollow