{"id":"UBUNTU-CVE-2026-62303","details":"Pistache is a high-performance REST toolkit written in C++. From 0.0.5 through 0.4.26, `SegmentTreeNode::sanitizeResource()` in `src/server/router.cc` uses `std::regex_replace()` with the `//+` expression to collapse consecutive slashes. With libstdc++, a path containing tens of thousands of consecutive slash characters can recurse deeply enough to exhaust the stack and crash the process. `Router::route()`, `Router::addRoute()` and `Router::removeRoute()` reach this normalization. Unauthenticated remote exploitation is conditional on a deployment allowing sufficiently long request paths, such as by increasing `Endpoint::Options::maxRequestSize()` above the default 4096-byte limit or forwarding long paths through a front end. Direct router API use is also affected when attacker-controlled route or resource strings reach the normalizer. Native builds reproduced a crash around 24,000 consecutive slashes, although the exact threshold depends on the stack and standard library; the demonstrated failure is stack exhaustion rather than uninitialized-memory use. A source fix replaces recursive regular-expression normalization with an iterative pass, but no containing repository release was verified as of time of publication.","modified":"2026-11-04T03:30:33.776929408Z","published":"2026-11-03T00:00:00Z","upstream":["CVE-2026-62303"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-62303"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-62303"},{"type":"REPORT","url":"https://github.com/pistacheio/pistache/security/advisories/GHSA-q474-pqcp-gqm5"},{"type":"REPORT","url":"https://github.com/pistacheio/pistache/commit/935461352403696f3ca0dbb9a7de7d2609e7ce91"}],"affected":[{"package":{"name":"pistache","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/pistache?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.0.5+ds-5","0.0.5+ds-5.1","0.0.5+ds-5.1build1","0.0.5+ds-5.1build2"],"ecosystem_specific":{"binaries":[{"binary_name":"libpistache0t64","binary_version":"0.0.5+ds-5.1build2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-62303.json"}},{"package":{"name":"pistache","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/pistache?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.4.26+ds-3"],"ecosystem_specific":{"binaries":[{"binary_version":"0.4.26+ds-3","binary_name":"libpistache0.4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-62303.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}