Path Traversal in deno (CVE-2026-49406)
Summary
Path traversal in deno (CVE-2026-49406). Confidential information can be exposed externally. Exploitable via main. Mitigation: upgrade to 2.7.12 or later.
Original description
The description as published by the source.
Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.12, when Deno was run in BYONM mode (nodeModulesDir: "manual"), the module resolver did not validate that a package's resolved entrypoint stayed within its node_modules// directory. A malicious package.json whose main field contained .. segments was able to resolve to an arbitrary path on disk, and the resolver then read that file without consulting the --allow-read allowlist. This let a require("evil-pkg") call return the contents of a file that a direct Deno.readTextFileSync(...) call would have been blocked from reading. This vulnerability is fixed in 2.7.12.
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-2026-49406 has been found in deno.
Attackers can target a specific entry point like main over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 5.5/10.
What to do: upgrade deno to 2.7.12 or later.
If unsure, ask your IT team or search "deno CVE-2026-49406" on the vendor's site.
CVE-2026-49406 (deno) — CWE-22 / CVSS v3 5.5
Attack vector: local / no user interaction
Attack surface: main / node_modules / require / Deno.readTextFileSync
Patched: 2.7.12 — 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 deno. Attackers reach the vulnerable code path via main.
Check the vendor advisory for the affected versions of deno. Attack surface: main / node_modules / require / Deno.readTextFileSync.
Severity: Medium (CVSS 5.5/10). Confidential information can be exposed externally.
Update to 2.7.12.
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 'deno' . 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 'deno' . | 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
deno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 deno to 2.7.12ステージング環境で 2.7.12 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
- advisory github.com
- package github.com
- web github.com