CVE-2026-102820

Summary

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 Software

VendorProductVersion RangeStatus
Eugenyrussh< 0.63.2affected
rustpageant< 0.2.3affected

Weaknesses

  • CWE-125: CWE-125: Out-of-bounds Read
  • CWE-789: CWE-789: Memory Allocation with Excessive Size Value

References