Path Traversal in org.http4s:http4s-server_2.12 (CVE-2026-69201)
Summary
Path traversal in org.http4s:http4s-server_2.12 (CVE-2026-69201). Confidential information can be exposed externally. Exploitable via ResourceService. Mitigation: upgrade to 0.23.35 or later.
Original description
The description as published by the source.
The static content handlers ResourceService and WebjarService URL decode each path segment and then reject only segments that are exactly "", ".", or "..". A percent-encoded separator (%2F) lets an attacker smuggle a ../ segment past that filter and escape the configured base, reading resources that should not be public.
On Windows, a similar attack exists with (%5C).
Impact
Disclosure of classpath or webjar resources outside the configured base.
Preconditions
- Application uses
ResourceService(with a non-root base path) orWebjarService - At least one classpath entry is served from a directory (e.g.
sbt run, exploded .war) - Backend forwards
%2F/%5Cwithout normalizing (e.g., Ember, Blaze)
Fixes
The patch rejects any decoded path segment containing / (%2F) or \ (%5C) with a 400 Bad Request in ResourceService and WebjarService.
FileService was not exploitable, but the same guards are applied for consistency and to remove its reliance on path normalization.
Workarounds
- Deploy as a fat jar, with no filesystem directories on the classpath.
- Front the service with a proxy that rejects/normalizes
%2Fand%5Cin the request path.
Source: NIST National Vulnerability Database 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-2026-69201 has been found in org.http4s:http4s-server_2.12.
Attackers can target a specific entry point like ResourceService over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 5.9/10.
What to do: upgrade org.http4s:http4s-server_2.12 to 0.23.35 or later.
If unsure, ask your IT team or search "org.http4s:http4s-server_2.12 CVE-2026-69201" on the vendor's site.
CVE-2026-69201 (org.http4s:http4s-server_2.12) — CWE-22 / CVSS v3 5.9
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: ResourceService / WebjarService / FileService
Patched: 0.23.35 — 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.
Path traversal (CWE-22) exists in org.http4s:http4s-server_2.12. Attackers reach the vulnerable code path via ResourceService without authentication.
Check the vendor advisory for the affected versions of org.http4s:http4s-server_2.12. Attack surface: ResourceService / WebjarService / FileService.
Severity: Medium (CVSS 5.9/10). Confidential information can be exposed externally.
Update to 0.23.35.
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. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで org.http4s:http4s-server_2.12 を使っているサービスとバージョンを洗い出す。
-
2Apply patch patch
Upgrade org.http4s:http4s-server_2.12 to 0.23.35ステージング環境で 0.23.35 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
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com