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.
History

Wed, 30 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 30 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
First Time appeared Eugeny
Eugeny russh
Rust
Rust pageant
Vendors & Products Eugeny
Eugeny russh
Rust
Rust pageant

Wed, 30 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Tue, 29 Sep 2026 18:30:00 +0000

Type Values Removed Values Added
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.
Title pageant: Out-of-bounds read / oversized allocation in `pageant` MemoryMap::read via a malicious Pageant agent (Windows)
Weaknesses CWE-125
CWE-789
References
Metrics cvssV3_1

{'score': 6.2, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-09-29T18:18:43.297Z

Updated: 2026-09-30T20:11:08.453Z

Reserved: 2026-09-29T17:25:25.264Z

Link: CVE-2026-102820

cve-icon Vulnrichment

Updated: 2026-09-30T20:10:35.312Z

cve-icon NVD

Status : Deferred

Published: 2026-09-29T19:17:23.820

Modified: 2026-09-30T21:17:05.797

Link: CVE-2026-102820

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-29T18:18:43Z

Links: CVE-2026-102820 - Bugzilla