CVE-2026-31842

EUVD-2026-19603
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.
HTTP Request/Response Smuggling
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 44.95%
Affected Products (NVD)
VendorProductVersion
tinyproxy_projecttinyproxy
𝑥
≤ 1.11.3
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
tinyproxy
bookworm
no-dsa
bookworm (security)
vulnerable
bullseye
postponed
bullseye (security)
vulnerable
forky
vulnerable
sid
vulnerable
trixie
no-dsa
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
tinyproxy
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
questing
ignored
resolute
needs-triage
trusty
needs-triage
xenial
ignored
Common Weakness Enumeration
References
https://datatracker.ietf.org/doc/html/rfc7230
https://github.com/tinyproxy/tinyproxy
https://github.com/tinyproxy/tinyproxy/issues/604