CVE-2026-81535

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Source
https://cve.org/CVERecord?id=CVE-2026-81535
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-81535.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-81535
Published
2026-10-07T02:39:27Z
Modified
2026-10-13T02:47:02Z
Severity
  • 6.3 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N CVSS Calculator
Summary
wolfSSH SSH client accepts unsolicited forwarded-tcpip channel opens without an authorization check
Details

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.

Database specific 
{
    "cna_assigner":  "wolfSSL",
    "cwe_ids":  [
        "CWE-862",
        "CWE-863"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/81xxx/CVE-2026-81535.json"
}
References

Affected packages

Git / github.com/wolfssl/wolfssh

Affected ranges

Type
GIT
Repo
https://github.com/wolfssl/wolfssh
Events
Introduced
ed97707a9c58d392fdbbbeaa1b3df0faa96d82d2
Fixed
8221e4ee48c93da6cea3325a91de2ecc00ae5f56
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "1.4.8"
        },
        {
            "fixed":  "1.6.0"
        }
    ],
    "source":  "AFFECTED_FIELD"
}

Affected versions

v1.*
v1.4.10-stable
v1.4.11-stable
v1.4.12-stable
v1.4.13-stable
v1.4.14-stable
v1.4.15-stable
v1.4.16
v1.4.17-stable
v1.4.18-stable
v1.4.19-stable
v1.4.20-stable
v1.4.21-stable
v1.4.22-stable
v1.4.8-stable
v1.4.9
v1.5.0-stable

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-81535.json"