MISP up to 2.5.41 session fixiation

Summaryinfo

A vulnerability has been found in MISP up to 2.5.41 and classified as critical. This vulnerability affects unknown code. The manipulation leads to session fixiation. This vulnerability is listed as CVE-2026-56425. The attack may be initiated remotely. There is no available exploit. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability, which was classified as critical, has been found in MISP up to 2.5.41. This issue affects an unknown part. The manipulation with an unknown input leads to a session fixiation vulnerability. Using CWE to declare the problem leads to CWE-384. Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

The Azure Active Directory (AAD) authentication implementation contained multiple weaknesses in its OAuth 2.0 authorization flow that could allow attackers to bypass important security guarantees provided by the protocol. The application used the PHP session identifier (session_id()) as the OAuth state parameter. Because session identifiers are long-lived authentication credentials, exposing them in OAuth redirect URLs could leak valid session tokens through browser history, HTTP Referer headers, reverse proxies, access logs, or third-party infrastructure involved in the authentication flow. If obtained by an attacker, the leaked session identifier could potentially be used for session hijacking. Additionally, the implementation did not regenerate the session identifier after successful authentication, leaving authenticated sessions susceptible to session fixation attacks where an attacker forces a victim to use a known session identifier before login and later reuses that identifier after authentication. The OAuth state value was also not implemented as a dedicated, single-use nonce. This weakened CSRF protections and increased the risk of replay attacks against the OAuth callback process. The authentication flow further failed to enforce HTTPS for the configured OAuth redirect URI. If a non-HTTPS redirect URI was used, OAuth authorization codes and access tokens could traverse the network in plaintext, exposing sensitive credentials to network attackers. Finally, OAuth error responses containing attacker-controlled GET parameters were logged verbatim. An attacker could inject control characters or crafted log content, leading to log forging, log injection, or corruption of audit records. The fix introduces: * A dedicated cryptographically random OAuth state value. * Single-use state validation and invalidation. * Constant-time state comparison using hash_equals(). * Session identifier rotation after successful authentication. * Enforcement of HTTPS-only redirect URIs. * Sanitized and length-limited logging of OAuth error parameters. AAD Authentication Plugin (OAuth 2.0 / Azure Active Directory integration)

The weakness was presented by Cormac Doherty as 146bc40ad6e10a44f01e8ed62d5f7bc9c06cc4fa. It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-56425 since 06/22/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available.

Applying the patch 146bc40ad6e10a44f01e8ed62d5f7bc9c06cc4fa is able to eliminate this problem. The bugfix is ready for download at github.com.

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Productinfo

Name

• MISP

Version

• 2.5.0
• 2.5.1
• 2.5.2
• 2.5.3
• 2.5.4
• 2.5.5
• 2.5.6
• 2.5.7
• 2.5.8
• 2.5.9
• 2.5.10
• 2.5.11
• 2.5.12
• 2.5.13
• 2.5.14
• 2.5.15
• 2.5.16
• 2.5.17
• 2.5.18
• 2.5.19
• 2.5.20
• 2.5.21
• 2.5.22
• 2.5.23
• 2.5.24
• 2.5.25
• 2.5.26
• 2.5.27
• 2.5.28
• 2.5.29
• 2.5.30
• 2.5.31
• 2.5.32
• 2.5.33
• 2.5.34
• 2.5.35
• 2.5.36
• 2.5.37
• 2.5.38
• 2.5.39
• 2.5.40
• 2.5.41

License

• open-source

Website

• Product: https://github.com/MISP/MISP/

CPE 2.3info

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CPE 2.2info

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