CVE-2026-33309
Authenticated RCE via arbitrary file write in Langflow API.
Is CVE-2026-33309 being exploited?
Not confirmed. CVE-2026-33309 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 11% probability of exploitation in the next 30 days.
How severe is CVE-2026-33309?
CVE-2026-33309 is rated Critical with a CVSS score of 9.9. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-33309?
Yes. A fix has been recorded for CVE-2026-33309. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-33309 affect?
CVE-2026-33309 affects Langflow 1.2.0-1.8.1. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-33309?
Upgrade to 1.9.0+
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated attacker can write arbitrary files on the host via /api/v2/files/, enabling remote code execution.
Patch when possible
- affected>= 1.2.0 and < 1.9.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.