Vulnerability in datamodel-code-generator (CVE-2026-55391)
Summary
Vulnerability in datamodel-code-generator (CVE-2026-55391). Confidential information can be exposed externally. Exploitable via httpx. Mitigation: upgrade to 0.63.0 or later.
Original description
The description as published by the source.
Summary
datamodel-code-generator's anti-SSRF guard validates the resolved IP of a fetch target once and then lets httpx perform its own independent DNS resolution to connect, so the validated address is never pinned. A hostname that resolves to a public IP at validation time and a private IP at connection time (DNS rebinding) bypasses the guard and reaches loopback, link-local cloud-metadata endpoints (169.254.169.254), and other internal services — even with the default allow_private_network=False. This is a server-side request forgery reachable when the tool fetches an attacker-influenced URL (remote $ref, or --url).
Details
In src/datamodel_code_generator/http.py, get_body() calls _validate_url_for_fetch(), which resolves the host via _get_ips_from_host() (socket.getaddrinfo) and rejects non-global addresses:
ips = _get_ips_from_host(host) # resolution #1 (validation)
if not ips: return
if all(_is_safe_ip(ip) for ip in ips): return
raise SchemaFetchError(...) # blocks private/link-local/reserved
It then connects with a separate, independent resolution:
response = httpx.get(current_url, ...) # resolution #2 (connection) -- NOT pinned to #1
Nothing ties the connection to the IP that passed validation. Between the two resolutions a low-TTL attacker-controlled record can flip from a public address (passes the guard) to a private one (used by the connection). The redirect-handling loop…
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-2026-55391 has been found in datamodel-code-generator.
Attackers can target a specific entry point like httpx over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: upgrade datamodel-code-generator to 0.63.0 or later.
If unsure, ask your IT team or search "datamodel-code-generator CVE-2026-55391" on the vendor's site.
CVE-2026-55391 (datamodel-code-generator) — CWE-350 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: httpx / socket.getaddrinfo
Patched: 0.63.0 — 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-350) exists in datamodel-code-generator. Attackers reach the vulnerable code path via httpx without authentication.
Check the vendor advisory for the affected versions of datamodel-code-generator. Attack surface: httpx / socket.getaddrinfo.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
Update to 0.63.0.
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 'datamodel-code-generator' . 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
-
1Identify exposure identify
grep -r 'datamodel-code-generator' . | 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
datamodel-code-generator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 datamodel-code-generator to 0.63.0ステージング環境で 0.63.0 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 gist.github.com
- advisory nvd.nist.gov
- package github.com
- package pypi.org
- web github.com
- web github.com
- web github.com