CVE-2026-56425Network attack vector

Session hijacking via OAuth state identifier misuse

Published Jun 22, 2026 · Updated Jun 22, 2026

Session fixation in MISP 2.5.41 and earlier allows remote attackers to hijack authenticated sessions through the AAD authentication plugin. The plugin sends the PHP session identifier as OAuth state, retains it after login, permits HTTP redirect URIs, and writes raw callback errors to logs. Exploitation requires a victim's AAD sign-in or an HTTP redirect configuration; exposed or fixed identifiers grant session access, while crafted errors can forge audit entries.

CVSS severity9.3
Critical
EPSS probability0.46%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Session fixation in MISP 2.5.41 and earlier allows remote attackers to hijack authenticated sessions through the AAD authentication plugin. The plugin sends the PHP session identifier as OAuth state, retains it after login, permits HTTP redirect URIs, and writes raw callback errors to logs. Exploitation requires a victim's AAD sign-in or an HTTP redirect configuration; exposed or fixed identifiers grant session access, while crafted errors can forge audit entries.

The record

CVE
CVE-2026-56425
Published
Jun 22, 2026
Updated
Jun 22, 2026
Vendor
MISP Project
Product
MISP
Classifications
CWE-384, T1539
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2.5.41

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MISP Project · MISPversion=0 <=2.5.41

Published CVSS scores

9.3CIRCLCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-384Session Fixation
T1539Steal Web Session Cookie

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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