Eugeny pageant up to 0.2.2 PageantStream pageant/src/wmmessage.rs MemoryMap::read out-of-bounds

Summaryinfo

A vulnerability labeled as problematic has been found in Eugeny pageant up to 0.2.2. Impacted is the function MemoryMap::read of the file pageant/src/wmmessage.rs of the component PageantStream. Such manipulation leads to out-of-bounds. This vulnerability is referenced as CVE-2026-102820. The attack can only be performed from a local environment. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Eugeny pageant up to 0.2.2. Affected by this issue is the function MemoryMap::read of the file pageant/src/wmmessage.rs of the component PageantStream. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-102820 since 09/29/2026. The exploitation is known to be easy. The attack needs to be approached locally. There are known technical details, but no exploit is available.

Upgrading to version 0.2.3 eliminates this vulnerability.

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Productinfo

Vendor

• Eugeny

Name

• pageant

Version

• 0.2.0
• 0.2.1
• 0.2.2

CPE 2.3info

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CPE 2.2info

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