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.
Metrics
Affected Vendors & Products
References
History
Tue, 13 Oct 2026 17:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Wolfssh
Wolfssh wolfssh |
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| CPEs | cpe:2.3:a:wolfssh:wolfssh:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Wolfssh
Wolfssh wolfssh |
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| Metrics |
cvssV3_1
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Wed, 07 Oct 2026 19:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Wed, 07 Oct 2026 04:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Wolfssl
Wolfssl wolfssh |
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| Vendors & Products |
Wolfssl
Wolfssl wolfssh |
Wed, 07 Oct 2026 02:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | wolfSSH SSH client accepts unsolicited forwarded-tcpip channel opens without an authorization check | |
| Weaknesses | CWE-862 CWE-863 |
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| References |
| |
| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: wolfSSL
Published: 2026-10-07T02:39:27.830Z
Updated: 2026-10-07T18:37:36.186Z
Reserved: 2026-08-26T23:09:37.634Z
Link: CVE-2026-81535
Updated: 2026-10-07T18:37:30.970Z
Status : Analyzed
Published: 2026-10-07T03:16:59.567
Modified: 2026-10-13T17:36:15.900
Link: CVE-2026-81535
No data.