{"id":"UBUNTU-CVE-2026-102820","details":"pageant provides a [PageantStream] type that implements [AsyncRead] and [AsyncWrite] traits and can be used to talk to a running Pageant instance. Prior to pageant 0.2.3, the Windows pageant crate's pageant/src/wmmessage.rs MemoryMap::read function trusts a peer-controlled u32 response length supplied through the 8192-byte Pageant shared-memory mapping reached by AgentClient::connect_pageant. A local process that impersonates the Pageant window can make query_pageant_direct allocate up to approximately 4 GiB and copy beyond the mapped view, reliably crashing a russh client and conditionally exposing adjacent committed memory. This issue is fixed in pageant 0.2.3.","modified":"2026-10-17T12:57:56.055802022Z","published":"2026-09-29T19:17:00Z","upstream":["CVE-2026-102820"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-102820"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-102820"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/security/advisories/GHSA-g4mp-vgx3-xrvm"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/commit/5d566989ebabfdebfe6b33243d31765a0812260b"},{"type":"REPORT","url":"https://github.com/Eugeny/russh/releases/tag/v0.63.2"}],"affected":[{"package":{"name":"rust-russh","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/rust-russh?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.57.1-2"],"ecosystem_specific":{"binaries":[{"binary_name":"librust-russh-dev","binary_version":"0.57.1-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-102820.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}