Vulnerability in github.com/getkin/kin-openapi (CVE-2026-100351)
Summary
Vulnerability in github.com/getkin/kin-openapi (CVE-2026-100351). Confidential information can be exposed externally. Exploitable via GET /public. Mitigation: upgrade to 0.147.0 or later.
Original description
The description as published by the source.
Summary
openapi3filter.ValidationHandler.Middleware validates requests with kin-openapi's
legacy router, which selects an OpenAPI operation from the decoded URL.Path. The
method is documented as implementing gorilla/mux.MiddlewareFunc, but a downstream
gorilla/mux router configured with UseEncodedPath() selects its handler from the
encoded representation (URL.RawPath).
An unauthenticated request such as /public%2Fstatus can therefore be validated as an
intentionally public operation (/public/status) and then dispatched to a protected
operation (/{id}). The configured, rejecting AuthenticationFunc is never invoked,
and the protected downstream handler runs.
This is distinct from GHSA-r277-6w6q-xmqw. The behavior below uses an explicit
authentication callback that rejects missing credentials and remains reproducible
after the v0.144.0 fix for the unsafe default callback.
Affected products
- Product:
github.com/getkin/kin-openapi - Component:
openapi3filter.ValidationHandler.Middleware - Confirmed post-GHSA affected releases: v0.144.0, v0.145.0, and v0.146.0
- Reporter attestation: each listed release was checked out separately, the attached
single-file test was copied intoopenapi3filter/, and that test passed; maintainers
should independently confirm the version range - Confirmed affected development revision:
d33e44e67734dcde81b576582185e1343fb3985d - v0.143.0 also reproduces this mechanism, but GHSA-r277-6w6q-xmqw already provides a…
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-2026-100351 has been found in github.com/getkin/kin-openapi.
Attackers can target a specific entry point like GET /public over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.4/10.
What to do: upgrade github.com/getkin/kin-openapi to 0.147.0 or later.
If unsure, ask your IT team or search "github.com/getkin/kin-openapi CVE-2026-100351" on the vendor's site.
CVE-2026-100351 (github.com/getkin/kin-openapi) — CWE-289 / CVSS v3 7.4
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: GET /public / GET /ordinary / URL.Path / URL.RawPath
Patched: 0.147.0 — 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-289) exists in github.com/getkin/kin-openapi. Attackers reach the vulnerable code path via GET /public without authentication.
Check the vendor advisory for the affected versions of github.com/getkin/kin-openapi. Attack surface: GET /public / GET /ordinary / URL.Path / URL.RawPath.
Severity: High (CVSS 7.4/10). Confidential information can be exposed externally.
Update to 0.147.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual GET /public requests with malformed payloads or SQL meta-characters. Run grep -r 'github.com/getkin/kin-openapi' . 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 'github.com/getkin/kin-openapi' . | 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
github.com/getkin/kin-openapiを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'GET /public' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /publicへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade github.com/getkin/kin-openapi to 0.147.0ステージング環境で 0.147.0 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と、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against GET /public on staging to confirm patch closes the vector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 Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
- REDHAT Red Hat
- web github.com
- web nvd.nist.gov
- web security-advisories@github.com
- web security-advisories@github.com
- web github.com