CVE-2026-40087
unknown
CVSS v3
—
CVSS v4 NEW
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VIR risk
—
Description
LangChain has incomplete f-string validation in prompt templates
Predictions
Exploit likelihood
30%
Patch ETA
—
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| PyPI | langchain-core | <0.3.84 | 0.3.84 |
| PyPI | langchain-core | >=1.0.0a1,<1.2.28 | 1.2.28 |
References
- https://github.com/langchain-ai/langchain/security/advisories/GHSA-926x-3r5x-gfhw
- https://nvd.nist.gov/vuln/detail/CVE-2026-40087
- https://github.com/langchain-ai/langchain/pull/36612
- https://github.com/langchain-ai/langchain/pull/36613
- https://github.com/langchain-ai/langchain/commit/6bab0ba3c12328008ddca3e0d54ff5a6151cd27b
- https://github.com/langchain-ai/langchain/commit/af2ed47c6f008cdd551f3c0d87db3774c8dfe258
- https://github.com/langchain-ai/langchain
- https://github.com/langchain-ai/langchain/releases/tag/langchain-core%3D%3D0.3.84
- https://github.com/langchain-ai/langchain/releases/tag/langchain-core%3D%3D1.2.28
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.