CVE-2026-23941: CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') in Erlang OTP
CVE-2026-23941 is a high-severity HTTP Request Smuggling vulnerability in the Erlang OTP inets httpd module. The vulnerability arises because the server does not reject or normalize duplicate Content-Length headers, using the earliest header for body parsing, while common reverse proxies use the last. This discrepancy violates RFC 9112 Section 6. 3 and can cause front-end/back-end desynchronization, potentially allowing attacker-controlled bytes to be interpreted as part of subsequent requests. It affects OTP versions from 17. 0 up to 28. 4. 1, including specific patch versions. No patch or official fix information is provided in the available data.
AI Analysis
Technical Summary
The vulnerability in Erlang OTP's inets httpd module (httpd_request:parse_headers/7) involves inconsistent handling of duplicate Content-Length headers in HTTP requests. The server uses the first Content-Length header to determine the request body length, whereas common reverse proxies like nginx, Apache httpd, and Envoy use the last Content-Length header. This inconsistency leads to front-end/back-end desynchronization, enabling HTTP Request Smuggling attacks. The issue violates RFC 9112 Section 6.3 and affects OTP versions 17.0 through 28.4.1 and related inets versions. No vendor advisory or patch links are provided, so remediation status is unclear.
Potential Impact
This vulnerability can cause front-end/back-end desynchronization in HTTP request processing, allowing an attacker to smuggle HTTP requests. This may lead to security issues such as request hijacking or bypassing security controls that rely on proper request parsing. The CVSS 4.0 score is 7 (high severity), indicating significant impact if exploited. There are no known exploits in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider deploying additional protections at the proxy or firewall level to detect or block HTTP request smuggling attempts, and review configurations of front-end proxies to ensure consistent handling of duplicate Content-Length headers.
CVE-2026-23941: CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') in Erlang OTP
Description
CVE-2026-23941 is a high-severity HTTP Request Smuggling vulnerability in the Erlang OTP inets httpd module. The vulnerability arises because the server does not reject or normalize duplicate Content-Length headers, using the earliest header for body parsing, while common reverse proxies use the last. This discrepancy violates RFC 9112 Section 6. 3 and can cause front-end/back-end desynchronization, potentially allowing attacker-controlled bytes to be interpreted as part of subsequent requests. It affects OTP versions from 17. 0 up to 28. 4. 1, including specific patch versions. No patch or official fix information is provided in the available data.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Erlang OTP's inets httpd module (httpd_request:parse_headers/7) involves inconsistent handling of duplicate Content-Length headers in HTTP requests. The server uses the first Content-Length header to determine the request body length, whereas common reverse proxies like nginx, Apache httpd, and Envoy use the last Content-Length header. This inconsistency leads to front-end/back-end desynchronization, enabling HTTP Request Smuggling attacks. The issue violates RFC 9112 Section 6.3 and affects OTP versions 17.0 through 28.4.1 and related inets versions. No vendor advisory or patch links are provided, so remediation status is unclear.
Potential Impact
This vulnerability can cause front-end/back-end desynchronization in HTTP request processing, allowing an attacker to smuggle HTTP requests. This may lead to security issues such as request hijacking or bypassing security controls that rely on proper request parsing. The CVSS 4.0 score is 7 (high severity), indicating significant impact if exploited. There are no known exploits in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider deploying additional protections at the proxy or firewall level to detect or block HTTP request smuggling attempts, and review configurations of front-end proxies to ensure consistent handling of duplicate Content-Length headers.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- EEF
- Date Reserved
- 2026-01-19T14:23:14.343Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 69b3d90e2f860ef943bac721
Added to database: 3/13/2026, 9:29:50 AM
Last enriched: 4/14/2026, 4:03:42 PM
Last updated: 4/27/2026, 8:55:53 PM
Views: 265
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