CVE-2026-107287: Pydantic AI is a Python agent framework for building applications and workflows with Generative AI

Q: How do I fix CVE-2026-107287?

pydantic ai: upgrade to 1.107.7, 2.52.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-107287 being exploited?

CVE-2026-107287 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-107287 affect?

CVE-2026-107287 affects pydantic ai. Severity is medium (CVSS 6.5). Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.7 and 2.52.0, the local web_fetch_tool and the WebFetch local fallback can consume excessive CPU and memory during H

Q: How urgent is CVE-2026-107287?

Priority 28/100. No elevated risk signals yet.

Routine

MEDIUM 6.5UPGRADE

CVE-2026-107287 is a medium-severity flaw (CVSS 6.5) affecting pydantic ai. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.7 and 2.52.0, the local web_fetch_tool and the WebFetch local fallback can consume excessive CPU and memory during HTML-to-Markdown conversion of attacker-controlled HTML containing deeply nested block elements. Conversion repeatedly reprocesses accumulated text and can greatly expand intermediate output before the returned-

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.3% (top 80%)
CISA exploited list	No
Weakness	CWE-400, CWE-407
Published	2026-10-08
Last modified	2026-10-14

Publisher (CNA): GitHub, Inc. · Vendor: pydantic

Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-10-08 16:17 UTCPublished CVE record published
2026-10-14 01:17 UTCUpdated Record last modified

pydantic pydantic ai UPGRADE

Affected: >= 1.77.0 and < 1.107.7 · >= 2.0.0 and < 2.52.0

Fixed in: 1.107.7, 2.52.0

Safe to downgrade to: a release before 1.77.0

1. Check installed version

pip show pydantic-ai

2. UPGRADE to 1.107.7

pip install --upgrade "pydantic-ai>=1.107.7"

3. If no update is available yet, DOWNGRADE to a release before 1.77.0

pip index versions pydantic-ai pip install "pydantic-ai<1.77.0"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-107287?

pydantic ai: upgrade to 1.107.7, 2.52.0. Exact commands for each OS are on this page.

Is CVE-2026-107287 being exploited?

CVE-2026-107287 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-107287 affect?

CVE-2026-107287 affects pydantic ai. Severity is medium (CVSS 6.5). Pydantic AI is a Python agent framework for building applications and workflows with Generative AI. From 1.77.0 until 1.107.7 and 2.52.0, the local web_fetch_tool and the WebFetch local fallback can consume excessive CPU and memory during H

How urgent is CVE-2026-107287?

Priority 28/100. No elevated risk signals yet.

Software pages

Python vulnerabilities

Related CVEs

CVE-2026-107292 MEDIUM 6.4 UPGRADE Pydantic AI is a Python agent framework for building applications and workflows with Generative AI
CVE-2026-107286 HIGH 7.5 UPGRADE Pydantic AI is a Python agent framework for building applications and workflows with Generative AI
CVE-2026-107288 LOW 3.7 UPGRADE Pydantic AI is a Python agent framework for building applications and workflows with Generative AI
CVE-2026-107289 MEDIUM 6.8 UPGRADE Pydantic AI is a Python agent framework for building applications and workflows with Generative AI
CVE-2026-107290 MEDIUM 6.5 UPGRADE Pydantic AI is a Python agent framework for building applications and workflows with Generative AI

References

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