{"id":"CVE-2026-55255","published":"2026-06-23T17:17:08Z","modified":"2026-10-25T23:10:00Z","title":"Langflow Authorization Bypass Through User-Controlled Key Vulnerability","vendor":"Langflow","product":"Langflow","tier":"core","eol":null,"description":{"text":"Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, an Insecure Direct Object Reference (IDOR) vulnerability in /api/v1/responses endpoint allows an authenticated attacker to execute any flow belonging to another user by specifying the victim's flow ID in the request. This vulnerability is fixed in 1.9.1.","provenance":"source","from":"NVD"},"summary":{"text":"Langflow, a tool for building and deploying AI-powered agents and workflows, contains an insecure direct object reference in its /api/v1/responses endpoint before version 1.9.1, which is the affected component. An authenticated attacker can execute flows belonging to other users by supplying the victim's flow ID in the request, so exploitation requires only a valid account over network access and no user interaction.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:14:26Z"},"cvss":{"score":8.4,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L","provenance":"source","from":"NVD"},"epss":{"score":0.00887,"percentile":0.59248,"date":"2026-10-30","provenance":"source"},"kev":{"dateAdded":"2026-07-07","dueDate":"2026-07-10","ransomware":false,"requiredAction":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","notes":"https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-55255","provenance":"source"},"vulncheckKev":{"dateAdded":"2026-06-26","exploitedFirstSeen":"2026-06-26","ransomware":false,"evidence":[{"url":"https://webflow.sysdig.com/blog/understanding-langflow-cve-2026-55255-and-why-higher-cvss-vulnerabilities-arent-always-the-most-exploited","date":"2026-06-26"},{"url":"https://previdian.com/CVE-2026-55255","date":"2026-07-07"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2026-07-07"},{"url":"https://www.resecurity.com/es/blog/article/exploiting-langflows-validatecode-endpoint-for-remote-code-execution","date":"2026-07-29"},{"url":"https://www.recordedfuture.com/blog/july-2026-cve-landscape","date":"2026-08-07"},{"url":"https://www.acn.gov.it/portale/documents/20119/1300791/Operational_Summary_lug26_CLEAR.pdf/88b05799-3e4c-f3ed-4a42-d9e68e080604?t=1787220905144","date":"2026-08-20"},{"url":"https://expel.com/blog/the-ai-cve-exploitation-evidence-story-headlines-are-scarier-than-reality/","date":"2026-08-27"},{"url":"https://www.vulncheck.com/blog/pwning-the-ai-stack","date":"2026-08-28"}],"evidenceTotal":8,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 31, 2026","url":"https://otx.alienvault.com/pulse/6ae4aefab0c2191cecd41862","created":"2026-10-30"},{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"}],"provenance":"machine"},"cwes":[{"id":"CWE-639","name":"Authorization Bypass Through User-Controlled Key"}],"references":[{"url":"https://github.com/langflow-ai/langflow/commit/2c9f498d664a3c32698b57d7c5e752625291060e","tags":["Patch"]},{"url":"https://github.com/langflow-ai/langflow/pull/12832","tags":["Issue Tracking","Patch"]},{"url":"https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2","tags":["Exploit","Mitigation","Vendor Advisory"]},{"url":"https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2","tags":["Exploit","Mitigation","Vendor Advisory"]},{"url":"https://webflow.sysdig.com/blog/understanding-langflow-cve-2026-55255-and-why-higher-cvss-vulnerabilities-arent-always-the-most-exploited","tags":["Third Party Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-55255","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: remote exploit of public-facing API endpoint","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"allows an authenticated attacker to execute any flow belonging to another user","start":182,"end":260}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1005","name":"Data from Local System","tactics":["collection"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: accesses other users' flows and data","mappingType":"primary_impact","evidence":[{"from":"description","quote":"execute any flow belonging to another user by specifying the victim's flow ID","start":218,"end":295}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[{"ecosystem":"PyPI","package":"langflow","vulnerableRanges":["<1.9.1","<1.9.2"],"patched":["1.9.1","1.9.2"],"from":["GHSA-qrpv-q767-xqq2","PYSEC-2026-221"],"provenance":"source"}],"advisories":[{"id":"GHSA-qrpv-q767-xqq2","url":"https://github.com/advisories/GHSA-qrpv-q767-xqq2","severity":"HIGH","ecosystem":"PyPI","package":"langflow","vulnerableRanges":["<1.9.1"],"patched":["1.9.1"],"provenance":"source","from":"GHSA"}],"euvd":{"id":"EUVD-2026-38517","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-38517","exploited":true,"exploitedSince":"2026-07-07","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":["https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2"],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1005"],"provenance":"ai"}],"timeline":[{"date":"2026-06-23","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55255","provenance":"source"},{"date":"2026-06-26","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://webflow.sysdig.com/blog/understanding-langflow-cve-2026-55255-and-why-higher-cvss-vulnerabilities-arent-always-the-most-exploited","provenance":"source"},{"date":"2026-07-07","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2026-07-07","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-38517","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":14},"priority":{"score":65.7,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":5.0,"detail":"added 127 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":11.85,"detail":"percentile 0.5925"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 NVD reference tagged Exploit"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":5.88,"detail":"base score 8.4"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}