Vulnerability · Published Apr 7, 2026 · Assigned by TuranSec
CVE-2026-31842Tinyproxy HTTP request parsing desynchronization via case-sensitive Transfer-Encoding handling
High 7.5
In plain English
A high-severity security flaw in Tinyproxy from Tinyproxy Project. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities).
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.6%top 51.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | tinyproxy | no fix listed | DEBIAN-CVE-2026-31842 |
| Debian:13 | tinyproxy | no fix listed | DEBIAN-CVE-2026-31842 |
| Debian:14 | tinyproxy | no fix listed | DEBIAN-CVE-2026-31842 |
| Ubuntu:24.04:LTS | tinyproxy | no fix listed | UBUNTU-CVE-2026-31842 |
| Ubuntu:25.10 | tinyproxy | no fix listed | UBUNTU-CVE-2026-31842 |
| Ubuntu:26.04:LTS | tinyproxy | no fix listed | UBUNTU-CVE-2026-31842 |
| Ubuntu:26.10 | tinyproxy | no fix listed | UBUNTU-CVE-2026-31842 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Tinyproxy Project | Tinyproxy | 0 – through 1.11.3 |
Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- Upstream issue report and reproduction details issue-tracking, technical-description, third-party-advisory
- Tinyproxy upstream project product
- RFC 7230: transfer-coding names are case-insensitive technical-description