MISP misp-stix up to 2026.7.8 Parser state issue

Summaryinfo

A vulnerability marked as critical has been reported in MISP misp-stix up to 2026.7.8. This affects an unknown function of the component Parser. Performing a manipulation results in state issue. This vulnerability was named CVE-2026-77761. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability classified as critical has been found in MISP misp-stix up to 2026.7.8. This affects an unknown code of the component Parser. The manipulation with an unknown input leads to a state issue vulnerability. CWE is classifying the issue as CWE-371. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

A parser state isolation vulnerability in misp-stix could cause data from a previously processed STIX document to be retained and incorporated into the MISP event generated from a subsequent document when the same parser instance is reused. Several STIX 1 and STIX 2 parser components maintained per-document state that was not completely cleared between conversions. In the STIX 2 parser, galaxy and galaxy-cluster information, including custom galaxy clusters, could survive a parser reset and subsequently be associated with objects from another bundle. The STIX 1 parsers were affected by the same underlying state-management issue. Depending on the parser type, retained information could include galaxies, references, passive DNS bookkeeping, package titles, dates, and timestamps. As a result, parsing a second STIX package with an already-used parser could produce a MISP event containing information that was present only in the previously processed package. For example, a generated event could inherit passive DNS records from an earlier document, reference unrelated galaxy information, combine titles from different packages, or use timestamps originating from another conversion. The issue primarily affects applications using the misp-stix API directly and reusing parser instances across independent STIX documents. Normal conversion entry points that instantiate a new parser for each file are not affected by this particular reuse scenario. An attacker able to influence documents processed by such a long-lived parser could potentially cause information from one conversion to contaminate a subsequent MISP event. This can affect the integrity of generated threat intelligence, resulting in incorrect associations, misleading contextual information, or unrelated indicators being attributed to an event. In environments where consecutive documents have different access controls or distribution scopes, the retained state could additionally result in limited disclosure of information from a previously processed document. Successful exploitation depends on the consuming application reusing the same parser instance and on the ordering of processed documents, which increases attack complexity. No direct availability impact or code execution is involved.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-77761 since 08/21/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. The technical details are unknown and an exploit is not publicly available.

Applying the patch f08373dd is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-63883). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• MISP

Name

• misp-stix

Version

• 2026.7.0
• 2026.7.1
• 2026.7.2
• 2026.7.3
• 2026.7.4
• 2026.7.5
• 2026.7.6
• 2026.7.7
• 2026.7.8

License

• open-source

Website

• Product: https://github.com/MISP/misp-stix/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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