CVE-2026-30827
Essential information
- Published
- 07/03/2026 06:16
- Modified
- 07/03/2026 06:16
- Author
- —
- Creator
- —
- CVSS
- 7.5 HIGH (v3.1)
- CISA KEV
- No
- CWE
- —
- CVSS vector
-
—
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H—
CVSS metrics
- Access vector
- —
- Access complexity
- —
- Authentication
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- Confidentiality impact
- —
- Integrity impact
- —
- Availability impact
- —
- Exploitability
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- NETWORK
- Attack complexity
- LOW
- Privileges required
- NONE
- User interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality impact
- NONE
- Integrity impact
- NONE
- Availability impact
- HIGH
- Exploit code maturity
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- —
- Attack complexity
- —
- Attack requirements
- —
- Privileges required
- —
- User interaction
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- Confidentiality (V)
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- Confidentiality (S)
- —
- Integrity (V)
- —
- Integrity (S)
- —
- Availability (V)
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- Availability (S)
- —
- Exploit maturity
- —
Description
express-rate-limit is a basic rate-limiting middleware for Express. In versions starting from 8.0.0 and prior to versions 8.0.2, 8.1.1, 8.2.2, and 8.3.0, the default keyGenerator in express-rate-limit applies IPv6 subnet masking (/56 by default) to all addresses that net.isIPv6() returns true for. This includes IPv4-mapped IPv6 addresses (::ffff:x.x.x.x), which Node.js returns as request.ip on dual-stack servers. Because the first 80 bits of all IPv4-mapped addresses are zero, a /56 (or any /32 to /80) subnet mask produces the same network key (::/56) for every IPv4 client. This collapses all IPv4 traffic into a single rate-limit bucket: one client exhausting the limit causes HTTP 429 for all other IPv4 clients. This issue has been patched in versions 8.0.2, 8.1.1, 8.2.2, and 8.3.0.
NVD status
- Status
- Received — CVE has been recently published to the CVE List and has been received by the NVD.
- Source
- [email protected]
- NVD
- View on NVD
Affected products (CPE)
| Product | CPE |
|---|---|
| expressjs / express-rate-limit | cpe:2.3:a:expressjs:express-rate-limit:<8.0.2:*:*:*:*:*:*:* |
| expressjs / express-rate-limit | cpe:2.3:a:expressjs:express-rate-limit:8.0.0:*:*:*:*:*:*:* |
| expressjs / express-rate-limit | cpe:2.3:a:expressjs:express-rate-limit:8.1.0:*:*:*:*:*:*:* |
| expressjs / express-rate-limit | cpe:2.3:a:expressjs:express-rate-limit:8.2.0:*:*:*:*:*:*:* |