CVE-2026-81535 (GCVE-0-2026-81535)
Vulnerability from cvelistv5 – Published: 2026-10-07 02:39 – Updated: 2026-10-07 18:37
VLAI
EPSS
VEX
Title
wolfSSH SSH client accepts unsolicited forwarded-tcpip channel opens without an authorization check
Summary
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.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-07 18:37 UTC
Assigner
References
3 references
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| wolfSSL Inc. | wolfSSH |
Affected:
1.4.8 , ≤ 1.5.0
(semver)
|
guessed |
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