Vulnerability in tmp (CVE-2026-49982)
Summary
Vulnerability in tmp (CVE-2026-49982). Data can be tampered with by attackers. Exploitable via _assertPath. Mitigation: upgrade to 0.2.7 or later.
Original description
The description as published by the source.
tmp is a temporary file and directory creator for node.js. In version 0.2.6, the _assertPath guard added to tmp rejects only string values that contain the substring ... It is bypassed when prefix, postfix, or template is supplied as a non-string value (Array, Buffer, or any object) whose includes('..') returns falsy but whose stringification still contains ../. The value flows through Array.prototype.join/String coercion inside _generateTmpName and path.join(tmpDir, opts.dir, name), producing a final path that escapes tmpdir and creates a file or directory at an attacker-controlled location with the host process's privileges. This affects any application that forwards untrusted request data (a common pattern is JSON body fields or qs-parsed bracket-array query strings such as ?prefix[]=...) into tmp.file, tmp.fileSync, tmp.dir, tmp.dirSync, tmp.tmpName, or tmp.tmpNameSync without explicit type coercion. This vulnerability is fixed in 0.2.7.
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-2026-49982 has been found in tmp.
Attackers can target a specific entry point like _assertPath over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 8.2/10.
What to do: upgrade tmp to 0.2.7 or later.
If unsure, ask your IT team or search "tmp CVE-2026-49982" on the vendor's site.
CVE-2026-49982 (tmp) — CWE-20 / CVSS v3 8.2
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: _assertPath / prefix / postfix / template
Patched: 0.2.7 — 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-20) exists in tmp. Attackers reach the vulnerable code path via _assertPath without authentication.
Check the vendor advisory for the affected versions of tmp. Attack surface: _assertPath / prefix / postfix / template.
Severity: High (CVSS 8.2/10). Data can be tampered with by attackers.
Update to 0.2.7.
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 'tmp' . 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 'tmp' . | 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
tmp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 tmp to 0.2.7ステージング環境で 0.2.7 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
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Ubuntu UBUNTU-CVE-2026-49982 node-tmp
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com