Raw vector
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NSummary
CVE-2026-34454 is a low-severity Session Fixation (CWE-384) vulnerability in Oauth2 Proxy Project Oauth2 Proxy. Its CVSS base score is 3.5 (Low).
Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-12 (Session Termination) and SC-23 (Session Authenticity) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-22758
Vulnerability Data
OAuth2 Proxy is a reverse proxy that provides authentication using OAuth2 providers. A regression introduced in 7.11.0 prevents OAuth2 Proxy from clearing the session cookie when rendering the sign-in page. In deployments that rely on the sign-in page as part…
more
of their logout flow, a user may be shown the sign-in page while the existing session cookie remains valid, meaning the browser session is not actually logged out. On shared workstations or devices, a subsequent user could continue to use the previous user's authenticated session. Deployments that use a dedicated logout/sign-out endpoint to terminate sessions are not affected. This issue is fixed in 7.15.2
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
—
V4.4.4V7.6.2
Mitigating Controls (NIST 800-53 r5) AI
AC-12 directly requires automatic session termination after a defined period, structurally preventing reuse of expired session identifiers.
Requires protection of session authenticity, which directly stops an attacker from using a stolen or fixed session identifier after authentication.
Enforces that only properly authorized (i.e., freshly authenticated) sessions can access resources, making a pre-existing fixed session ID unusable.
Forces re-authentication under defined conditions, which should result in issuance of a fresh session identifier and invalidation of any prior one.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Credential lifecycle management directly includes enforcing session expiration to prevent reuse.
Proper authentication processes must invalidate prior session identifiers to prevent fixation attacks.
Authorization policy enforcement and review covers terminating stale sessions to limit access scope.
Protecting and verifying identity assertions encompasses secure handling and regeneration of session tokens.
Configuration baselines can enforce session regeneration and timeout settings that block fixation.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect session-fixation issues, yet the weakness absence does not replace comprehensive testing.
Access-control policy can mandate session invalidation on re-authentication, but does not prescribe the technical mechanism.
Identity-management procedures can require new session tokens after login, yet the control is broader than session handling.
Authentication-information rules can include session-token lifecycle requirements, but the control focuses on credential management.
Secure-SDLC requirement can embed session-fixation checks, but eliminating the weakness does not satisfy the full SDLC control.
Application-security requirements can specify session handling, yet the weakness fix alone does not meet the broader requirement.