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CVE-2026-12763 IBM CVE debrief

IBM Langflow OSS versions 1.0.0 through 1.11.5 are vulnerable due to improper cache key isolation in the MCP Tools component, allowing authenticated attackers to access another user's MCP server context. Defenders should prioritize patching and assessing exposure in their environments. This vulnerability has a medium severity and requires immediate attention to prevent unauthorized access. Affected deployments should be identified, and owners assigned for follow-up. Official advisories and CVE records provide details for remediation.

Vendor
IBM
Product
Langflow OSS
CVSS
MEDIUM 4.2
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-14
Original CVE updated
2026-11-03
Advisory published
2026-09-14
Advisory updated
2026-11-03

Who should care

Defenders responsible for IBM Langflow OSS deployments, security teams, and operators should assess exposure and prioritize patching. This vulnerability impacts environments using IBM Langflow OSS versions 1.0.0 through 1.11.5. Affected operators and platforms should review and update security configurations for the MCP Tools component. Vulnerability management and security teams should verify and apply patches, and

Why it matters

CVE-2026-12763 is a medium-severity vulnerability in IBM Langflow OSS that allows an authenticated attacker to access another user's MCP server context. Defenders should prioritize verifying and applying patches, assessing exposure, and reviewing security configurations.

  • Verify and apply patches to prevent unauthorized access
  • Assess exposure in environments using IBM Langflow OSS
  • Review and update security configurations for MCP Tools component

Technical summary

The vulnerability in IBM Langflow OSS allows an authenticated attacker to access another user's MCP server context due to improper cache key isolation in the MCP Tools component. This issue affects IBM Langflow OSS versions 1.0.0 through 1.11.5. Technical details indicate a medium-severity vulnerability that requires patching and exposure assessment. No exploit details are publicly available, and defenders should focus on applying patches and reviewing security configurations.

Defensive priority

Defenders should prioritize verifying and applying patches for IBM Langflow OSS versions 1.0.0 through 1.11.5, and assess exposure in their environments.

Recommended defensive actions

  • Verify and apply patches for IBM Langflow OSS versions 1.0.0 through 1.11.5
  • Assess exposure in environments using IBM Langflow OSS
  • Review and update security configurations for MCP Tools component

Evidence notes

The CVE record and NVD entry provide details on the vulnerability in IBM Langflow OSS. IBM has provided a vendor advisory with patch information. The vulnerability affects IBM Langflow OSS versions 1.0.0 through 1.11.5. Defenders should verify and apply patches, assess exposure in their environments, and review security configurations for the MCP Tools component. Evidence is limited to public sources, and further verification is recommended.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-12763 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-12763

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-12763 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-12763

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.