CVE-2026-107290
What it is
Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.6 and 2.44.0, the local web_fetch_tool and the WebFetch local fallback process server-controlled responses with quadratic title extraction, whitespace normalization, and ordered-list numbering. An attacker-controlled page of modest size can therefore block the event loop for an extended period, stalling other agent runs and requests, while unsupported codecs or excessive HTML or JSON nesting can abort an individual run. This issue is fixed in versions 1.107.6 and 2.44.0.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 6.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Weakness
- CWE-1333
- Record status
- Analyzed
Affected
- Pydantic Ai < 1.107.6
- Pydantic Ai < 2.44.0
Attack profile CVSS 3.1 · 6.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-107290.md and follow it. Check whether this project is affected by CVE-2026-107290. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/pydantic/pydantic-ai/commit/2faa6181d8a17d83bc9516d035c5270db8730fa0
- https://github.com/pydantic/pydantic-ai/commit/9cdc952e4c3319e85a3e04f2de49fbbb765bd38b
- https://github.com/pydantic/pydantic-ai/commit/a93ea5226be1e93ae13131ae3f22287190411389
- https://github.com/pydantic/pydantic-ai/commit/c3fd1cc1f15fdbf750d78e4e3ec1e8b4d6a3d920
- https://github.com/pydantic/pydantic-ai/commit/fb92ccfc3ca2735dab877e2ed73856681bf72ad1
- https://github.com/pydantic/pydantic-ai/pull/8397
- https://github.com/pydantic/pydantic-ai/pull/8399
- https://github.com/pydantic/pydantic-ai/pull/8418
- https://github.com/pydantic/pydantic-ai/pull/84332
- https://github.com/pydantic/pydantic-ai/pull/8434
References
- https://github.com/pydantic/pydantic-ai/commit/2faa6181d8a17d83bc9516d035c5270db8730fa0
- https://github.com/pydantic/pydantic-ai/commit/9cdc952e4c3319e85a3e04f2de49fbbb765bd38b
- https://github.com/pydantic/pydantic-ai/commit/a93ea5226be1e93ae13131ae3f22287190411389
- https://github.com/pydantic/pydantic-ai/commit/c3fd1cc1f15fdbf750d78e4e3ec1e8b4d6a3d920
- https://github.com/pydantic/pydantic-ai/commit/fb92ccfc3ca2735dab877e2ed73856681bf72ad1
- https://github.com/pydantic/pydantic-ai/pull/8397
- https://github.com/pydantic/pydantic-ai/pull/8399
- https://github.com/pydantic/pydantic-ai/pull/8418
- https://github.com/pydantic/pydantic-ai/pull/84332
- https://github.com/pydantic/pydantic-ai/pull/8434
- https://github.com/pydantic/pydantic-ai/releases/tag/v1.107.6
- https://github.com/pydantic/pydantic-ai/releases/tag/v2.44.0
- https://github.com/pydantic/pydantic-ai/security/advisories/GHSA-fpf4-vwcp-v4hp