Path Traversal in wisp (CVE-2026-28807)
Summary
Path traversal in wisp (CVE-2026-28807). Confidential information can be exposed externally. Mitigation: upgrade to 2.2.1 or later.
Original description
The description as published by the source.
Summary
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in gleam-wisp wisp allows arbitrary file read via percent-encoded path traversal.
The wisp.serve_static function is vulnerable to path traversal because sanitization runs before percent-decoding. The encoded sequence %2e%2e passes through string.replace unchanged, then uri.percent_decode converts it to .., which the OS resolves as directory traversal when the file is read.
An unauthenticated attacker can read any file readable by the application process in a single HTTP request, including application source code, configuration files, secrets, and system files.
This issue affects wisp: from 2.1.1 before 2.2.1.
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-2026-28807 has been found in wisp.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: upgrade wisp to 2.2.1 or later.
If unsure, ask your IT team or search "wisp CVE-2026-28807" on the vendor's site.
CVE-2026-28807 (wisp) — CWE-22 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 2.2.1 — 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 wisp.
Check the vendor advisory for the affected versions of wisp.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
Update to 2.2.1.
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 'wisp' . 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 'wisp' . | 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
wisp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 wisp to 2.2.1ステージング環境で 2.2.1 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 hex.pm
- patch github.com
- web cna.erlef.org
- web osv.dev
- web github.com
- web github.com