OpenWrt uhttpd Header Parsing client.c client_parse_header request smuggling

CVSS Meta Temp Score
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CTI Interest Score
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5.1$0-$5k1.56

Summaryinfo

A vulnerability was found in OpenWrt uhttpd and classified as problematic. Affected by this vulnerability is the function client_parse_header of the file client.c of the component Header Parsing. Such manipulation leads to request smuggling. This vulnerability is referenced as CVE-2026-55614. It is possible to launch the attack remotely. No exploit is available. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability was found in OpenWrt uhttpd (the affected version is unknown) and classified as problematic. Affected by this issue is the function client_parse_header of the file client.c of the component Header Parsing. The manipulation with an unknown input leads to a request smuggling vulnerability. Using CWE to declare the problem leads to CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. Impacted is integrity. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-55614 since 06/17/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available.

Applying the patch ae015e099986ceace44975cb69629841a2d58d37/6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 is able to eliminate this problem.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Vendor

Name

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Request smuggling
CWE: CWE-444
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: ae015e099986ceace44975cb69629841a2d58d37/6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837

Timelineinfo

06/17/2026 CVE reserved
10/30/2026 +135 days Advisory disclosed
10/30/2026 +0 days VulDB entry created
10/30/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CNA: GitHub_M
CVE: CVE-2026-55614 (🔒)

GCVE (CVE): GCVE-0-2026-55614
GCVE (VulDB): GCVE-100-429440

Entryinfo

Created: 10/30/2026 23:34
Changes: 10/30/2026 23:34 (69)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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