CVE-2026-55614
uhttpd vulnerable to HTTP request smuggling via case-sensitive Transfer-Encoding matching
uhttpd is a small HTTP server. In unpatched repository snapshots, client_parse_header() in client.c lowercases header names but compares the Transfer-Encoding value to chunked using case-sensitive strcmp. A mixed-case transfer-coding token is accepted without enabling r->transfer_chunked, despite transfer-coding tokens being case-insensitive. On a keep-alive connection, the chunked POST body is left unread and request-shaped body bytes are parsed as another HTTP request, permitting HTTP request smuggling and boundary desynchronization. Commits ae015e099986ceace44975cb69629841a2d58d37 and 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 patch the issue.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.9
uhttpd vulnerable to HTTP request smuggling via case-sensitive Transfer-Encoding matching
uhttpd is a small HTTP server. In unpatched repository snapshots, client_parse_header() in client.c lowercases header names but compares the Transfer-Encoding value to chunked using case-sensitive strcmp. A mixed-case transfer-coding token is accepted without enabling r->transfer_chunked, despite transfer-coding tokens being case-insensitive. On a keep-alive connection, the chunked POST body is left unread and request-shaped body bytes are parsed as another HTTP request, permitting HTTP request smuggling and boundary desynchronization. Commits ae015e099986ceace44975cb69629841a2d58d37 and 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 patch the issue.
- Record
CVE-2026-55614- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-444
- Updated
- 2026-11-02
EUVDEUVD-2026-114562
6.9
uhttpd is a small HTTP server. In unpatched repository snapshots, client_parse_header() in client.c lowercases header names but compares the Transfer-Encoding value to chunked using case-sensitive strcmp. A mixed-case transfer-coding token is accepted without enabling r->transfer_chunked, despite transfer-coding tokens being case-insensitive. On a keep-alive connection, the chunked POST body is left unread and request-shaped body bytes are parsed as another HTTP request, permitting HTTP request smuggling and boundary desynchronization. Commits ae015e099986ceace44975cb69629841a2d58d37 and 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 patch the issue.
- Record
EUVD-2026-114562- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-06
NVD
6.9
uhttpd is a small HTTP server. In unpatched repository snapshots, client_parse_header() in client.c lowercases header names but compares the Transfer-Encoding value to chunked using case-sensitive strcmp. A mixed-case transfer-coding token is accepted without enabling r->transfer_chunked, despite transfer-coding tokens being case-insensitive. On a keep-alive connection, the chunked POST body is left unread and request-shaped body bytes are parsed as another HTTP request, permitting HTTP request smuggling and boundary desynchronization. Commits ae015e099986ceace44975cb69629841a2d58d37 and 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 patch the issue.
- Record
CVE-2026-55614- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-444
- Updated
- 2026-11-03
OSV
6.9
uhttpd vulnerable to HTTP request smuggling via case-sensitive Transfer-Encoding matching
uhttpd is a small HTTP server. In unpatched repository snapshots, client_parse_header() in client.c lowercases header names but compares the Transfer-Encoding value to chunked using case-sensitive strcmp. A mixed-case transfer-coding token is accepted without enabling r->transfer_chunked, despite transfer-coding tokens being case-insensitive. On a keep-alive connection, the chunked POST body is left unread and request-shaped body bytes are parsed as another HTTP request, permitting HTTP request smuggling and boundary desynchronization. Commits ae015e099986ceace44975cb69629841a2d58d37 and 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 patch the issue.
- Record
CVE-2026-55614- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-444
- Updated
- 2026-11-04
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | NVD, OSV | |
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-55614 is a medium vulnerability (CVSS 6.9) in Openwrt Uhttpd, published October 30, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.40%, the 33rd percentile. No source names a fixed version.
References
github.com/openwrt/uhttpd/security/advisories/GHSA-mcfg-c4r7-pjpf
github.com/openwrt/uhttpd/commit/6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837
github.com/openwrt/uhttpd/commit/ae015e099986ceace44975cb69629841a2d58d37
github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55614.json
nvd.nist.gov/vuln/detail/CVE-2026-55614