Vulnerability in ts-deepmerge (CVE-2026-12644)
Summary
Vulnerability in ts-deepmerge (CVE-2026-12644). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 8.0.0 or later.
Original description
The description as published by the source.
Versions of the package ts-deepmerge before 8.0.0 are vulnerable to Uncaught Exception due to the improper handling of built-in Object.prototype methods (such as toString, valueOf). When user-controlled input contains these keys with non-function values, the resulting merged object becomes broken — any string context operation throws a TypeError, crashing the application.
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-2026-12644 has been found in ts-deepmerge.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade ts-deepmerge to 8.0.0 or later.
If unsure, ask your IT team or search "ts-deepmerge CVE-2026-12644" on the vendor's site.
CVE-2026-12644 (ts-deepmerge) — CWE-248 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 8.0.0 — 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-248) exists in ts-deepmerge.
Check the vendor advisory for the affected versions of ts-deepmerge.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to 8.0.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'ts-deepmerge' . 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 'ts-deepmerge' . | 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
ts-deepmerge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 ts-deepmerge to 8.0.0ステージング環境で 8.0.0 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 nvd.nist.gov
- package github.com
- web github.com
- web gist.github.com
- web security.snyk.io
- web github.com