MISP up to 2.5.45 Homepage Validation redirect

Summaryinfo

A vulnerability, which was classified as problematic, has been found in MISP up to 2.5.45. This affects an unknown part of the component Homepage Validation. The manipulation leads to redirect. This vulnerability is listed as CVE-2026-86351. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in MISP up to 2.5.45 and classified as problematic. This issue affects an unknown functionality of the component Homepage Validation. The manipulation with an unknown input leads to a redirect vulnerability. Using CWE to declare the problem leads to CWE-601. A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks. Impacted is integrity. The summary by CVE is:

Affected versions of MISP validate the user-configurable homepage by checking only whether the supplied path begins with /. That check is insufficient because protocol-relative URLs such as //attacker.example also begin with / but resolve to an external origin in browsers. The vulnerable homepage value can be stored as a user setting and later used by the post-login routing logic. The commit explicitly identifies //attacker.example as a payload that passed validation and was emitted to the Location header after login. The fix introduces a shared InternalRedirectValidator that rejects URLs containing a host, scheme, userinfo, unsafe leading // or /\, malformed URLs, and control characters. It also revalidates homepage settings on read so legacy or internally written unsafe values cannot bypass the new storage-time validation. Version affected: ≤2.5.45

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-86351 since 09/07/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/07/2026). MITRE ATT&CK project uses the attack technique T1204.001 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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
• 2.5.42
• 2.5.43
• 2.5.44
• 2.5.45

License

• open-source

Website

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

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion