MISP misp-stix up to 2026.7.8 STIX Import sys.exit resource consumption

Summaryinfo

A vulnerability was found in MISP misp-stix up to 2026.7.8. It has been classified as problematic. This affects the function sys.exit of the component STIX Import. Performing a manipulation results in resource consumption. This vulnerability is reported as CVE-2026-77755. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, was found in MISP misp-stix up to 2026.7.8. This affects the function sys.exit of the component STIX Import. The manipulation with an unknown input leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. The summary by CVE is:

A denial-of-service vulnerability was identified in misp-stix when processing attacker-controlled STIX 1 or STIX 2 documents. The STIX import code used sys.exit() to handle several parsing and loading failures. Because SystemExit inherits from BaseException rather than Exception, these failures bypassed the exception handlers used by callers of the library. As a result, a malformed STIX document could terminate a long-running importer process instead of returning a recoverable parsing error. Additionally, no limit was imposed on the size of STIX documents before parsing. A submitted document was therefore read and materialised in memory before its validity or type was evaluated. Depending on the document and parsing path, processing could consume approximately two to seven times the input size in memory, allowing a sufficiently large STIX document to cause excessive memory and CPU consumption and potentially terminate or severely degrade the importing service. An attacker able to provide STIX content to a MISP-STIX import workflow could exploit either condition to affect availability. A malformed document could cause abnormal process termination through an uncaught SystemExit, while a large document could exhaust resources during deserialisation and conversion. The fixes replace process-terminating sys.exit() calls with catchable exceptions such as STIXLoadingError and MissingSTIXContentError, and extend exception handling around the complete STIX detection and conversion process. The importer also now enforces an input-size limit before parsing. The default maximum is 100 MB, can be adjusted by callers, and can explicitly be disabled when required. STIX 1 inputs are additionally checked for the expected root element before the complete XML tree is constructed. ImpactSuccessful exploitation can cause: * termination of a long-running MISP-STIX importer; * excessive memory allocation; * excessive CPU consumption; * degradation or temporary unavailability of services relying on the converter; * interruption of batch or automated STIX ingestion workflows.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-77755 since 08/21/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Applying the patch e8e732ad is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-63881). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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/

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