CVE-2026-18891
Auth bypass in IBM Langflow allows remote execution of flows and data access
Is CVE-2026-18891 being exploited?
Not confirmed. CVE-2026-18891 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 0.31% probability of exploitation in the next 30 days.
How severe is CVE-2026-18891?
CVE-2026-18891 is rated High with a CVSS score of 8.2. 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-2026-18891?
Yes. A fix has been recorded for CVE-2026-18891. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-18891 affect?
CVE-2026-18891 affects IBM Langflow OSS 1.0.0 through 1.11.1. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-18891?
Apply vendor patch immediately; restrict/disable external access and monitor logs.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attacker can bypass authentication to execute arbitrary flows and access sensitive information in Langflow OSS 1.0.0–1.11.1.
Immediate action required
- affected>= 1.0.0 and <= 1.11.1
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.