{"id":"UBUNTU-CVE-2026-8711","details":"NGINX JavaScript has a vulnerability when the js_fetch_proxy directive is configured with at least one client-controlled NGINX variable (for example, $http_*, $arg_*, $cookie_*) and a location invoking the ngx.fetch() operation from NGINX JavaScript. An unauthenticated attacker can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.","modified":"2026-06-18T00:30:06.943595702Z","published":"2026-05-19T15:16:00Z","related":["USN-8425-1"],"upstream":["CVE-2026-8711"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-8711"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-8711"},{"type":"REPORT","url":"https://my.f5.com/manage/s/article/K000161307"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8425-1"}],"affected":[{"package":{"name":"libnginx-mod-js","ecosystem":"Ubuntu:Pro:26.04:LTS","purl":"pkg:deb/ubuntu/libnginx-mod-js?arch=source&distro=esm-apps%2Fresolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.9.4-1ubuntu0.1~esm1"}]}],"versions":["0.9.1-1ubuntu2","0.9.1-1ubuntu3","0.9.4-1~build1","0.9.4-1","0.9.4-1build1","0.9.4-1build2"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro","binaries":[{"binary_name":"libnginx-mod-http-js","binary_version":"0.9.4-1ubuntu0.1~esm1"},{"binary_name":"libnginx-mod-stream-js","binary_version":"0.9.4-1ubuntu0.1~esm1"},{"binary_version":"0.9.4-1ubuntu0.1~esm1","binary_name":"njs"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-8711.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"},{"type":"Ubuntu","score":"medium"}]}