Tinyproxy HTTP request parsing desynchronization via case-sensitive Transfer-Encoding handling
Summary
| CVE | CVE-2026-31842 |
|---|---|
| State | PUBLISHED |
| Assigner | TuranSec |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-07 12:16:21 UTC |
| Updated | 2026-08-10 12:17:14 UTC |
| Description | Tinyproxy through 1.11.3 is vulnerable to HTTP request parsing desynchronization due to a case-sensitive comparison of the Transfer-Encoding header in src/reqs.c. The is_chunked_transfer function uses strcmp to compare the header value against "chunked", even though RFC 7230 specifies that transfer-coding names are case-insensitive. |
Risk And Classification
Primary CVSS: v4.0 8.7 HIGH from 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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
EPSS: 0.008990000 probability, percentile 0.562660000 (date 2026-08-10)
Problem Types: CWE-444 | CWE-444 CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | Secondary | 8.7 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 8.7 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| 3.1 | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 2.0 | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | Secondary | 7.8 | AV:N/AC:L/Au:N/C:N/I:N/A:C | |
| 2.0 | CNA | CVSS | 7.8 | AV:N/AC:L/Au:N/C:N/I:N/A:C |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
NoneIntegrity
NoneAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v2.0 Breakdown
Access Vector
NetworkAccess Complexity
LowAuthentication
NoneConfidentiality
NoneIntegrity
NoneAvailability
CompleteAV:N/AC:L/Au:N/C:N/I:N/A:C
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Tinyproxy Project | Tinyproxy | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Tinyproxy Project | Tinyproxy | affected 1.11.3 custom | all |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/tinyproxy/tinyproxy | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | github.com | Product |
| datatracker.ietf.org/doc/html/rfc7230 | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | datatracker.ietf.org | Exploit, Technical Description |
| github.com/tinyproxy/tinyproxy/issues/604 | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | github.com | Exploit, Issue Tracking |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Muxammadiyev G'iyosiddin (en)
There are currently no legacy QID mappings associated with this CVE.