{"id":"UBUNTU-CVE-2026-31842","details":"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.","modified":"2026-08-13T03:00:18.217316983Z","published":"2026-04-07T12:16:00Z","upstream":["CVE-2026-31842"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-31842"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-31842"},{"type":"REPORT","url":"https://datatracker.ietf.org/doc/html/rfc7230"},{"type":"REPORT","url":"https://github.com/tinyproxy/tinyproxy"}],"affected":[{"package":{"name":"tinyproxy","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/tinyproxy?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.8.3-3ubuntu1","1.8.3-3ubuntu14.04.1~esm1","1.8.3-3ubuntu14.04.1~esm2","1.8.3-3ubuntu14.04.1~esm3"],"ecosystem_specific":{"binaries":[{"binary_name":"tinyproxy","binary_version":"1.8.3-3ubuntu14.04.1~esm3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-31842.json"}},{"package":{"name":"tinyproxy","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/tinyproxy?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.8.3-3ubuntu1","1.8.3-3ubuntu16.04.1~esm1","1.8.3-3ubuntu16.04.1~esm2","1.8.3-3ubuntu16.04.1~esm3"],"ecosystem_specific":{"binaries":[{"binary_name":"tinyproxy","binary_version":"1.8.3-3ubuntu16.04.1~esm3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-31842.json"}},{"package":{"name":"tinyproxy","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/tinyproxy?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.8.4-2","1.8.4-3","1.8.4-5","1.8.4-5ubuntu0.1~esm1","1.8.4-5ubuntu0.1~esm2","1.8.4-5ubuntu0.1~esm3"],"ecosystem_specific":{"binaries":[{"binary_name":"tinyproxy","binary_version":"1.8.4-5ubuntu0.1~esm3"},{"binary_version":"1.8.4-5ubuntu0.1~esm3","binary_name":"tinyproxy-bin"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-31842.json"}},{"package":{"name":"tinyproxy","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/tinyproxy?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.0-2","1.10.0-4","1.10.0-4ubuntu0.1","1.10.0-4ubuntu0.2"],"ecosystem_specific":{"binaries":[{"binary_name":"tinyproxy","binary_version":"1.10.0-4ubuntu0.2"},{"binary_name":"tinyproxy-bin","binary_version":"1.10.0-4ubuntu0.2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-31842.json"}},{"package":{"name":"tinyproxy","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/tinyproxy?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.0-5","1.11.0-1","1.11.0-1ubuntu0.1~esm1","1.11.0-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_version":"1.11.0-1ubuntu0.1~esm2","binary_name":"tinyproxy"},{"binary_name":"tinyproxy-bin","binary_version":"1.11.0-1ubuntu0.1~esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-31842.json"}},{"package":{"name":"tinyproxy","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/tinyproxy?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.11.1-2.1","1.11.1-3","1.11.1-3ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_name":"tinyproxy","binary_version":"1.11.1-3ubuntu0.1"},{"binary_version":"1.11.1-3ubuntu0.1","binary_name":"tinyproxy-bin"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-31842.json"}},{"package":{"name":"tinyproxy","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/tinyproxy?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.11.2-1"],"ecosystem_specific":{"binaries":[{"binary_name":"tinyproxy","binary_version":"1.11.2-1"},{"binary_version":"1.11.2-1","binary_name":"tinyproxy-bin"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-31842.json"}},{"package":{"name":"tinyproxy","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/tinyproxy?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.11.2-1","1.11.2-1build1","1.11.3-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.11.3-1","binary_name":"tinyproxy"},{"binary_version":"1.11.3-1","binary_name":"tinyproxy-bin"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-31842.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V4","score":"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"},{"type":"Ubuntu","score":"medium"}]}