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CVE PROGRAM SOURCE RECORD6.2 Medium

CVE-2026-102820

pageant: Out-of-bounds read / oversized allocation in `pageant` MemoryMap::read via a malicious Pageant agent (Windows)

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Eugeny russh

  • < 0.63.2affected

rust pageant

  • < 0.2.3affected

References