CVE Watch6 ago 2026

CVE-2026-5430

The JWT authentication mechanism accepts tokens signed with algorithms other than those explicitly configured or supported. This allows an a

CVSS

10.0

Crítico

EPSS

0.2%

p13

KEV

—

Exploit Today

0-100

Publicado: 6 ago 2026 · Última mod.: 6 ago 2026 · CWE-347

EPSS · 30d

0.2%EPSS · 30 días0.2%

2026-08-062026-08-07

Descripción técnica

The JWT authentication mechanism accepts tokens signed with algorithms other than those explicitly configured or supported. This allows an attacker to craft a JWT with an unsupported algorithm, which is then incorrectly validated, leading to unauthorized access. Successful exploitation of this vulnerability may result in unauthorized access to the system, including the potential compromise of administrative accounts and full account takeover. The CVSS score is adjusted to 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) in single-tenant deployments, reflecting that the impact is contained within a single security authority boundary.

Referencias oficiales

security.docs.wso2.comhttps://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5328/

CVEs relacionados

CVECVSSEPSSKEVRExplotTítuloVis.

CVE-2026-58262—

—

——0Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.20, header signature verification counts the unused padding bits of the PubKeysBitmap toward the two-thirds validator quorum. These padding bits do not correspond to any validator and are ignored by the actual BLS aggregate-signature check, so a malicious or compromised block producer can set them to reach the required quorum while gathering fewer genuine validator signatures than the protocol demands. As a result, nodes that import or intercept the header accept it as correctly signed without a real two-thirds quorum, weakening consensus safety and undermining finality. This issue is fixed in version 1.7.20.19h CVE-2026-629187.5 ALT

22.2%

——7Improper verification of cryptographic signature in Microsoft Teams allows an unauthorized attacker to perform spoofing over a network.23h CVE-2026-628739.8 CRÍ

27.7%

——8Improper verification of cryptographic signature in Microsoft 365 Admin Center allows an unauthorized attacker to elevate privileges over a network.23h CVE-2026-75579.1 CRÍ

18.3%

——6An improper verification of cryptographic signature vulnerability in the SAML authentication module of Progress MarkLogic Server before 11.3.6 and 12.0.3 allows an unauthenticated remote attacker to bypass authentication and impersonate any user, including administrators. This vulnerability affects deployments with SAML single sign-on enabled.2d CVE-2026-164437.4 ALT

4.0%

——1A flaw was found in the SAML metadata import functionality of the keycloak-services component, which is the core engine for identity brokering in Red Hat Build of Keycloak. When importing identity provider metadata that lacks specific usage attributes for keys, the system incorrectly disables signature validation for SAML responses even if a signing certificate is provided. This issue allows an unauthenticated attacker to forge a SAML response and gain unauthorized access to a user account by knowing their external identifier.2d CVE-2026-185693.7 BAJ

5.8%

——2A flaw was found in the backchannel logout endpoint of the keycloak-services component, which is part of the Red Hat Build of Keycloak. This component handles authentication and session management for applications. The issue occurs when an OIDC identity provider is configured to skip signature validation. In this specific setup, the system incorrectly accepts logout requests that have no cryptographic signature. An attacker who knows certain technical details about a user's session can use this flaw to force that user to be logged out, potentially disrupting their work.2d