Sign in Sign up
JA · EN · FR
SecPulse
Categories
CVE-2026-9277 high CVSS 8.1

Command Injection in shell-quote (CVE-2026-9277)

Summary

Command injection in shell-quote (CVE-2026-9277). Successful exploitation can lead to full system takeover. Exploitable via envFn. Mitigation: upgrade to 1.8.4 or later.

Original description

The description as published by the source.

Summary

shell-quote's quote() function did not validate object-token inputs against the operator model used by parse(). The .op field was backslash-escaped character by character using /(.)/g, which in JavaScript does not match line terminators (\n, \r, U+2028, U+2029). A line terminator in .op therefore passed through unescaped into the output; POSIX shells treat a literal \n as a command separator, so any content after it would execute as a second command.

The vulnerable code path is reachable in two ways. Neither requires the parser to misbehave — parse() only emits ops from a fixed control set — but both are documented API surface:

  1. Direct construction. A caller builds { op: '...\n...' } from external input (e.g. a deserialized argument array) and passes it to quote().
  2. envFn return. parse(cmd, envFn) is documented to splice the return value of envFn into the result array when it is an object. An attacker-influenced data source consulted by envFn can introduce an object token whose .op reaches quote().

Impact

Shell command injection in callers that pass object tokens with attacker-influenced .op values to quote() and then hand the result to a shell. The preconditions are narrower than ordinary string injection — they require the caller to feed object tokens into quote() — but object tokens are a public, documented part of the API surface, and quote() is intended to be a shell-safety boundary.

PoC

`…

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-2026-9277 has been found in shell-quote.
Attackers can target a specific entry point like envFn over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 8.1/10.
What to do: upgrade shell-quote to 1.8.4 or later.
If unsure, ask your IT team or search "shell-quote CVE-2026-9277" on the vendor's site.

CVE-2026-9277 (shell-quote) — CWE-77 / CVSS v3 8.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: envFn / bash / dash / zsh
Patched: 1.8.4 — apply immediately
Workaround: Prior to upgrading, callers that build object tokens from untrusted input should validate .op against the parser's operator set themselves, and never construct { op } from attacker-controlled strings.
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.

❓ What is the problem

A vulnerability (CWE-77) exists in shell-quote. Attackers reach the vulnerable code path via envFn without authentication.

📍 Affected scope

Check the vendor advisory for the affected versions of shell-quote. Attack surface: envFn / bash / dash / zsh.

🔥 Severity

Severity: High (CVSS 8.1/10). Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to 1.8.4.

🛡️ Workaround

Workaround: Prior to upgrading, callers that build object tokens from untrusted input should validate .op against the parser's operator set themselves, and never construct { op } from attacker-controlled strings.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'shell-quote' . 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

  1. 1
    Identify exposure identify 
    grep -r 'shell-quote' . | 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 shell-quote を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Apply temporary workaround mitigate 
    Prior to upgrading, callers that build object tokens from untrusted input should validate `.op` against the parser's operator set themselves, and never construct `{ op }` from attacker-controlled strings.

    パッチが適用されるまでの応急処置として、Prior to upgrading, callers that build object tokens from untrusted input should validate .op against the parser's operator set themselves, and never construct { op } from attacker-controlled strings. を実施。回避策の副作用 (機能低下) を確認した上で。

  3. 3
    Apply patch patch 
    Upgrade shell-quote to 1.8.4

    ステージング環境で 1.8.4 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。

  4. 4
    Post-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

npm shell-quote
[{"type":"SEMVER","events":[{"introduced":"1.1.0"},{"fixed":"1.8.4"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details