Security Bulletin
Summary
A Time-of-Check to Time-of-Use (TOCTOU) vulnerability in IBM Langflow Desktop's SSRF protection allows authenticated attackers to bypass internal network access restrictions using DNS rebinding attacks. The validate_url_for_ssrf() function validates URLs using socket.getaddrinfo(), but httpx.AsyncClient() performs a separate DNS lookup during connection, creating a race condition. An attacker-controlled DNS rebinding domain with TTL=0 can return a public IP during validation (passing checks) but return a private IP (127.0.0.1, 192.168.x.x, 169.254.169.254) during the actual request, allowing unauthorized access to localhost services, internal networks, and cloud metadata endpoints. While IBM Langflow Desktop has DNS pinning infrastructure (validate_and_resolve_url() and DNSPinningNetworkBackend) designed to prevent this attack, the protection is not consistently applied across all code paths, making the SSRF protection bypassable in default configurations.
Vulnerability Details
CVEID: CVE-2026-3341
DESCRIPTION: IBM Langflow is vulnerable to server-side request forgery (SSRF). This may allow an authenticated attacker to send unauthorized requests from the system, potentially leading to network enumeration or facilitating other attacks.
CWE: CWE-918: Server-Side Request Forgery (SSRF)
CVSS Source: IBM
CVSS Base score: 5.4
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| IBM Langflow Desktop | 1.0.0-1.9.2 |
Remediation/Fixes
IBM strongly recommends addressing the vulnerability now by upgrading Langflow Desktop to version 1.9.3.
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
08 Jun 2026: Initial Publication
*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.
Disclaimer
According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.
Document Location
Worldwide
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Document Information
Modified date:
08 June 2026
Initial Publish date:
08 June 2026
UID
ibm17275444