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 products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Tinyproxy Project | Tinyproxy | ≤ 1.11.3 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | tinyproxy | No fix yet | — |
| Debian 13 | tinyproxy | No fix yet | — |
| Debian 12 | tinyproxy | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | tinyproxy | No fix yet | — |
| Ubuntu 26.04 LTS | tinyproxy | No fix yet | — |
| Ubuntu 25.10 | tinyproxy | No fix yet | — |
| Ubuntu 24.04 LTS | tinyproxy | No fix yet | — |
| Ubuntu 20.04 LTS | tinyproxy | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 22.04 LTS | tinyproxy | No fix yet | — |
| Ubuntu Pro 18.04 LTS | tinyproxy | No fix yet | — |
| Ubuntu Pro 16.04 LTS | tinyproxy | No fix yet | — |
| Ubuntu Pro 14.04 LTS | tinyproxy | No fix yet | — |
Advisories 1
- WID-SEC-2026-0999 Tinyproxy: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Apr 12, 2026
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