CVE-2026-73089
highpriority · track · 0EPSS 0.007 · 51 %ileDEEUFRUSEPSS · scored 2026-10-27
Browserslist is a configuration tool for sharing target browsers and Node.js versions between front-end tools. Prior to 4.28.7, index.js retains every distinct `(queries, context)` result in cache and every parseQueries() AST in parseCache without a size cap, TTL, or eviction, allowing an attacker who can influence repeated browserslist() query values, including valid since `<year>-<month>-<day>` queries, to bypass the caller-controlled BROWSERSLIST_DISABLE_CACHE mitigation and cause linear memory growth followed by an out-of-memory process crash. This issue is fixed in version 4.28.7.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (20)
Products and version ranges known to be affected.
advisories (3)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-3376Atlassian Bamboo, Bitbucket, Confluence, Fisheye/Crucible, Jira Software und Jira Service Management: Mehrere SchwachstellenDeutsch2026-09-15csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Atlassian Bamboo, Bitbucket, Confluence, Fisheye/Crucible, Jira Software und Jira Service Management ausnutzen, um beliebigen Programmcode auszuführen, Sicherheitsmaßnahmen zu umgehen, serverseitige Request-Forgery-Angriffe (SSRF) durchzuführen, Cross-Site-Scripting-Angriffe zu starten, sensible Informationen offenzulegen, Daten zu manipulieren oder Denial-of-Service-Zustände herbeizuführen.
- GHSA-c83g-rgw3-j3cxBrowserslist: Unbounded memory growth (no cache eviction) via distinct query results, leading to eventual OOM2026-09-01ghsa · osvUS
## Vulnerability Details **File**: `index.js` **Location**: `cache` (browserslist()'s result cache, line ~402) and `parseCache` (parseQueries()'s AST cache) ### Root Cause ```js 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 <year>-<month>-<day>` 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 <year>-<month>-<day>` queries (~330 KB total input, `--expose-gc` before/after measurement to rule out uncollected garbage) retained **over 50 MB** of heap permanently — roughly **150x** amplification, growing linearly with no cap observed up to 40,000 queries (52.3 MB). ### Attack Scenario Any long-running process (server, daemon, warm CI worker) that calls `browserslist()` with a query value that varies across requests/items and is influenced, even partially, by external input accumulates one cache entry per distinct value ever seen. An attacker who can influence that value across *many* requests (this is a volumetric attack, unlike the single-request DoS findings from this same research pass) sends a stream of cheap, distinct queries (e.g. `since 1900-01-01`, `since 1900-01-02`, ...) until the process runs out of memory and crashes. ### Recommended Fix (implemented and verified) Replace both plain-object caches with `Map`s bounded to a fixed maximum entry count, evicting the oldest entry once the cap is reached (`Map` preserves insertion order, so `.keys().next().value` is always oldest): ```js var CACHE_MAX_ENTRIES = 500 function boundedCacheSet(map, key, value) { if (map.size >= CACHE_MAX_ENTRIES) { map.delete(map.keys().next().value) } map.set(key, value) } var cache = new Map() var parseCache = new Map() ``` (read sites changed to `.has()`/`.get()`, write sites to `boundedCacheSet()`) **Verification**: - `NODE_ENV=test npx uvu test .test.js` → 301/301 pass unmodified (`test/cache.test.js` exercises `clearCaches()`/`BROWSERSLIST_DISABLE_CACHE` against `node.js`'s separate filesystem caches, unaffected here); confirmed a repeated identical call still returns the cached reference. - Re-ran the memory PoC post-fix: heap stayed flat at ~4.9 MB after 5,000, 10,000, 20,000, and 40,000 distinct `since`-date queries (was 10.5 → 16.5 → 28.4 → 52.3 MB pre-fix). ### Impact - **Who is affected**: Long-running processes calling `browserslist()` with query values that vary across requests/items and are influenced by external input. - **What an attacker achieves**: DoS via eventual out-of-memory crash, given sustained traffic over time (not a single small payload). - **Conditions required**: No authentication; requires volume rather than a single request, hence Medium rather than High severity. ### Verification Environment browserslist @ HEAD (== v4.28.6, current latest stable release) under local Node.js v20.19.5, run with `--expose-gc` for accurate heap measurement. ### Note Found during a broader review of this codebase in the same research pass that produced GHSA-rrmg-cfrq-23vv (parse.js algorithmic complexity), GHSA-g6p8-hj8g-x889 (baseline regexp ReDoS), GHSA-73wf-gq98-2v4g (normalizeStats crash/prototype write), and GHSA-h633-868p-5rfw (SCOPED_CONFIG__PATTERN ReDoS) — all single-request DoS vectors. This one is different in character (volumetric, not single-request) and is reported separately/scored lower accordingly.
- CERTFR-2026-AVI-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR
also known as (2)
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sources
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references (9)
External citations — patches, advisories, analysis.
- https://github.com/browserslist/browserslist/commit/f2931a3ff2a3a31abf84ef01a7400b270aad6405cnnvd
- https://github.com/browserslist/browserslist/releases/tag/4.28.7cnnvd
- https://github.com/browserslist/browserslist/security/advisories/GHSA-c83g-rgw3-j3cxcnnvd
- https://github.com/browserslist/browserslist/commit/f2931a3ff2a3a31abf84ef01a7400b270aad6405enisa_euvd
- https://github.com/browserslist/browserslist/releases/tag/4.28.7enisa_euvd
- https://github.com/browserslist/browserslist/security/advisories/GHSA-c83g-rgw3-j3cxenisa_euvd
- https://github.com/browserslist/browserslist/commit/f2931a3ff2a3a31abf84ef01a7400b270aad6405nvd
- https://github.com/browserslist/browserslist/releases/tag/4.28.7nvd
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