Vulnerability in pydantic-ai (CVE-2026-107287)
Summary
Vulnerability in pydantic-ai (CVE-2026-107287). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 2.52.0 or later.
Original description
The description as published by the source.
Summary
Applications using Pydantic AI's local web-fetch tool can experience excessive CPU and memory use when it converts attacker-controlled HTML. An agent must fetch the affected page; provider-native web fetching is not affected.
Details
Nested block elements cause HTML-to-Markdown conversion to reprocess accumulated text at each level and can greatly expand the intermediate output. The response-body limit bounds downloaded bytes, while the returned-content limit is applied only after conversion. On current releases, conversion runs in a worker thread but can still consume substantial resources and delay other work in the process. Older releases performed conversion on the event loop.
Mitigation
Upgrade to a patched release of pydantic-ai or pydantic-ai-slim. If you cannot upgrade yet, avoid using local web fetching for attacker-controlled HTML.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-107287 has been found in pydantic-ai.
Risk of unauthorized operations or information disclosure. CVSS score: 6.5/10.
What to do: upgrade pydantic-ai to 2.52.0 or later.
If unsure, ask your IT team or search "pydantic-ai CVE-2026-107287" on the vendor's site.
CVE-2026-107287 (pydantic-ai) — CWE-400 / CVSS v3 6.5
Attack vector: remote (network-reachable) / unauthenticated
Patched: 2.52.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-400) exists in pydantic-ai.
Check the vendor advisory for the affected versions of pydantic-ai.
Severity: Medium (CVSS 6.5/10). Risk of unauthorized operations or information disclosure.
Update to 2.52.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'pydantic-ai' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'pydantic-ai' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
pydantic-aiを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade pydantic-ai to 2.52.0ステージング環境で 2.52.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- package pypi.org
- package pypi.org
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com