Vulnerability in github.com/getkin/kin-openapi (CVE-2026-100354)
Summary
Vulnerability in github.com/getkin/kin-openapi (CVE-2026-100354). Risk of unauthorized operations or information disclosure. Exploitable via GET /test. Mitigation: upgrade to 0.149.0 or later.
Original description
The description as published by the source.
Summary
kin-openapi's spec loader and spec-time validator both handle circular schema references safely: the loader resolves circular $refs on purpose (to support recursive data structures), and Schema.validate() uses stack-based cycle detection. Validate() therefore accepts a schema whose allOf / anyOf / oneOf chain refers back to itself, returning no error.
The runtime validators do not have that protection. When such a schema is used for request or response validation, the recursion through the combinator chain is unbounded. In Go this produces a fatal stack overflow (runtime: goroutine stack exceeds ... limit / fatal error: stack overflow), which is not a recoverable panic. recover() cannot catch it, so net/http's per-connection recovery does not help. The entire process is terminated, including all goroutines serving unrelated clients.
Two independent unguarded recursion sites were confirmed:
openapi3/schema.go—visitJSON/visitXOFOperations(reached byVisitJSON, i.e. response validation and direct schema validation).openapi3filter/req_resp_decoder.go—decodeValue(reached first during request parameter decoding). The report also identifies the same gap inurlValuesDecoder.parseValueandbuildResObj/buildFromSchemas.
Details
Root Cause
Schema.validate() has cycle detection (openapi3/schema.go:1396):
func (schema *Schema) validate(ctx context.Context, stack []*Schema) ([]*Schema, error) {…
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-2026-100354 has been found in github.com/getkin/kin-openapi.
Attackers can target a specific entry point like GET /test over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade github.com/getkin/kin-openapi to 0.149.0 or later.
If unsure, ask your IT team or search "github.com/getkin/kin-openapi CVE-2026-100354" on the vendor's site.
CVE-2026-100354 (github.com/getkin/kin-openapi) — CWE-674 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: GET /test / allOf / anyOf / oneOf
Patched: 0.149.0 — 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-674) exists in github.com/getkin/kin-openapi. Attackers reach the vulnerable code path via GET /test without authentication.
Check the vendor advisory for the affected versions of github.com/getkin/kin-openapi. Attack surface: GET /test / allOf / anyOf / oneOf.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 0.149.0.
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 /test 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 /test' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /test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 0.149.0ステージング環境で 0.149.0 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 /test 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
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Ubuntu UBUNTU-CVE-2026-100354 golang-github-getkin-kin-openapi
References
- advisory nvd.nist.gov
- package github.com
- REDHAT Red Hat
- web github.com
- web github.com
- web github.com
- web github.com