Request smuggling via hidden framing headers
Published Aug 4, 2026 · Updated Aug 4, 2026
HTTP request smuggling in Node.js 22.23.1, 24.18.0, and 26.5.0 allows remote attackers to inject requests through forwarding proxies. The HTTP parser omits headers beyond maxHeadersCount or maxHeaderPairs from IncomingMessage views while retaining them for framing, hiding Content-Length as the body is forwarded. Exploitation requires a proxy that rebuilds outbound headers from those views, pipes the original body, and reuses a backend connection; ordinary non-proxy applications are unaffected.
Summary
What happened
HTTP request smuggling in Node.js 22.23.1, 24.18.0, and 26.5.0 allows remote attackers to inject requests through forwarding proxies. The HTTP parser omits headers beyond maxHeadersCount or maxHeaderPairs from IncomingMessage views while retaining them for framing, hiding Content-Length as the body is forwarded. Exploitation requires a proxy that rebuilds outbound headers from those views, pipes the original body, and reuses a backend connection; ordinary non-proxy applications are unaffected.
The record
- CVE
- CVE-2026-58044
- Published
- Aug 4, 2026
- Updated
- Aug 4, 2026
- Vendor
- Node.js
- Product
- Node.js
- Classifications
- CWE-444, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 4, 2026CVE publishedPublication date reported by the CVE source.
- Aug 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=22.23.1 <=22.23.1
- Affected versionversion=24.18.0 <=24.18.0
- Affected versionversion=26.5.0 <=26.5.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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