Sign in Sign up
JA · EN · FR
SecPulse
Categories
CVE-2026-73089 high CVSS 7.5

Vulnerability in browserslist (CVE-2026-73089)

Summary

Vulnerability in browserslist (CVE-2026-73089). Risk of unauthorized operations or information disclosure. Exploitable via index.js. Mitigation: upgrade to 4.28.7 or later.

Original description

The description as published by the source.

Vulnerability Details

File: index.js
Location: cache (browserslist()'s result cache, line ~402) and
parseCache (parseQueries()'s AST cache)

Root Cause

var cache = {}
var parseCache = {}

function browserslist(queries, opts) {
  ...
  var cacheKey = JSON.stringify([queries, context])
  if (cache[cacheKey]) return cache[cacheKey]
  ...
  if (!env.env.BROWSERSLIST_DISABLE_CACHE) { cache[cacheKey] = result }
  return result
}

function parseQueries(queries) {
  var cacheKey = JSON.stringify(queries)
  if (cacheKey in parseCache) return parseCache[cacheKey]
  var result = parseWithoutCache(QUERIES, queries)
  if (!env.env.BROWSERSLIST_DISABLE_CACHE) { parseCache[cacheKey] = result }
  ...
}

Every distinct (queries, context) pair is cached forever — no size cap,
TTL, or eviction. browserslist.clearCaches() never resets either object
(it only resets node.js's own filesystem caches); the only opt-out is the
BROWSERSLIST_DISABLE_CACHE env var, controlled by the calling
application, not an attacker.

Some short, valid queries amplify this badly. The since --
query type (/^since (\d+)-(\d+)-(\d+)$/i) accepts any digit
combination — Date.UTC() normalizes rather than rejects out-of-range
values — giving an effectively unbounded space of ~17-byte distinct cache
keys, each of which resolves to (and caches) a result close to the full
~8.5 KB browser list for any sufficiently old year.

Measured Impact

20,000 distinct since -- queries…

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-2026-73089 has been found in browserslist.
Attackers can target a specific entry point like index.js over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade browserslist to 4.28.7 or later.
If unsure, ask your IT team or search "browserslist CVE-2026-73089" on the vendor's site.

CVE-2026-73089 (browserslist) — CWE-770 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: index.js / cache / parseCache / node.js
Patched: 4.28.7 — 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.

❓ What is the problem

A vulnerability (CWE-770) exists in browserslist. Attackers reach the vulnerable code path via index.js without authentication.

📍 Affected scope

Check the vendor advisory for the affected versions of browserslist. Attack surface: index.js / cache / parseCache / node.js.

🔥 Severity

Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 4.28.7.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'browserslist' . 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 'browserslist' . | 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 browserslist 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 patch patch 
    Upgrade browserslist to 4.28.7

    ステージング環境で 4.28.7 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。

  3. 3
    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 browserslist
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.28.7"}]}]

References

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