CyberSecBulletin
CVE-2026-13448NVD status: Modified

Langflow OSS: Incomplete List of Disallowed Inputs

CVE-2026-13448 is a critical-severity incomplete list of disallowed inputs vulnerability in Langflow OSS from IBM, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Langflow OSS versions: 1.0.0 through 1.10.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.73% chance of exploitation within 30 days, higher than 55% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Langflow to 1.10.2 or a later version.
  2. Read the advisory on ibm.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
IBMLangflow OSS1.0.0 through 1.10.1Not stated
LangflowLangflow1.0.0 up to, but not including, 1.10.21.10.2

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.1HighCNA (us.ibm.com)
CVSS 3.19.8CriticalNVD

Official description

IBM Langflow OSS 1.0.0 through 1.10.1 Lanflow OSS contains an unauthenticated remote code execution vulnerability in the public flow build endpoint ( /api/v1/build_public_tmp/{flow_id}/flow ). The vulnerability stems from an incomplete denylist in the validate_public_flow_no_code_execution() function that fails to block several code-execution agent components including OpenDsStarAgent, CodeActAgentSmolagents, and CSVAgent.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incomplete List of Disallowed Inputs

The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete.

How developers prevent this class of flaw

  • Do not rely exclusively on detecting disallowed inputs. There are too many variants to encode a character, especially when different environments are used, so there is a high likelihood of missing some variants. Only use detection of disallowed inputs as a mechanism for detecting suspicious activity. Ensure that you are using other protection mechanisms that only identify good input - such as lists of allowed inputs - and ensure that you are properly encoding your outputs.

More Incomplete List of Disallowed Inputs vulnerabilities (CWE-184)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Langflow OSS

All Langflow OSS vulnerabilities

Recent Incomplete List of Disallowed Inputs vulnerabilities

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