# CVE-2026-90991: IBM Langflow OSS denial of service via resource exhaustion

Source: https://junglewise.ai/threats/cve-2026-90991-ibm-langflow-oss-1-0-0-through-1-12-4-could-allow-a-remote  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-29. Updated: 2026-10-29  
License: CC BY 4.0 with a link back

CVE-2026-90991 · Severity: medium · CVSS 6.5 · Published 2026-10-29

IBM Langflow OSS is an open-source application development platform that allows users to build AI workflows and applications. An authenticated attacker can exploit an uncontrolled resource allocation vulnerability to cause a denial of service, making the application unavailable to legitimate users. This requires the attacker to already have valid credentials to access the system.

Technologies: [IBM Langflow OSS](https://junglewise.ai/threats/technologies/langflow-oss). Vendors: [IBM](https://junglewise.ai/threats/vendors/ibm).

## Quick answers

**Is CVE-2026-90991 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-90991 being exploited in the wild.

**How severe is CVE-2026-90991?** Medium severity, with a CVSS score of 6.5, published 29 October 2026.

**Which products and versions are affected?** IBM Langflow OSS 1.0.0 through 1.12.4.

**Is there a fix for CVE-2026-90991?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-90991 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-90991?** Check whether you run IBM Langflow OSS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exists in Langflow OSS versions 1.0.0 through 1.12.4 due to allocation of resources without limits or throttling (CWE-770). An authenticated attacker can send requests that cause the application to allocate excessive resources, exhausting server capacity. The attack requires network access and valid authentication credentials; no user interaction is needed.

## Affected products

- IBM Langflow OSS 1.0.0 through 1.12.4

## Timeline

- 2026-10-29: disclosed

## References

- [https://www.ibm.com/support/pages/node/7293016](https://www.ibm.com/support/pages/node/7293016)

## Related threats

- [IBM Langflow OSS path traversal arbitrary file read and write](https://junglewise.ai/threats/cve-2026-97677-ibm-langflow-oss-1-0-0-through-1-12-2-an-authenticated-flow)
- [IBM Langflow OSS authentication bypass](https://junglewise.ai/threats/cve-2026-93680-ibm-langflow-oss-1-0-0-through-1-12-8-could-allow-a-remote)
- [IBM Langflow OSS path traversal arbitrary file overwrite](https://junglewise.ai/threats/cve-2026-77819-ibm-langflow-oss-1-0-0-through-1-12-3-could-allow-a-remote)
- [IBM Langflow OSS improper sanitization of secrets in exports](https://junglewise.ai/threats/cve-2026-77817-ibm-langflow-oss-1-0-0-through-1-12-4-could-allow-a-remote)
- [IBM Langflow OSS code injection in public workflow execution](https://junglewise.ai/threats/cve-2026-18894-ibm-langflow-oss-1-0-0-through-1-12-4-could-allow-a-remote)