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CVE PROGRAM SOURCE RECORD6.3 Medium

CVE-2026-81535

wolfSSH SSH client accepts unsolicited forwarded-tcpip channel opens without an authorization check

Description

In wolfSSH through 1.5.0 built with --enable-fwd, DoChannelOpen() in src/internal.c gates only direct-tcpip channel opens with the forwarding policy callback. forwarded-tcpip opens are admitted without an authorization check and are not capped in number, allowing a malicious SSH peer to make an endpoint allocate unbounded per-channel buffers for forwarding channels the application never authorized. A client also does not check a forwarded-tcpip open against the forwards it registered with a tcpip-forward request, as RFC 4254 section 7.2 requires, so a malicious server can open forwarding channels for addresses and ports the client never asked it to forward.

Affected products

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

wolfSSL Inc. wolfSSH

Default version status: unaffected

  • 1.4.8 to ≤ 1.5.0affected

References