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.
CVE-2026-81535
MEDIUMPre-NVD 6.36.3Trending — 4 sources updated this week
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 6.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: secondary
6.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.3Exploit: None knownExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 6.3
- EG Score
- 6.3MEDIUMlow confidence
- EG Risk
- 28EG Risk 28/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity63% × 45%Exploitation0% × 40%Automatability0% × 15%CISA SSVC: Track at every mission impact level.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 0.3%
- EPSS %ILE
- 18th
- KEV
- Not listed
CISA SSVCTrack at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
October 7, 2026
Last Modified
October 7, 2026
Advisory Details (3)
Auto-updated Oct 7, 2026Patch available. Sources: github_commit.
github_commit Patch Available
commit 79a7f299337a (wolfSSL/wolfssh)
Patch available: wolfSSL/wolfssh v1.6.0-stable (contains commit 79a7f299337a)
https://github.com/wolfSSL/wolfssh/commit/79a7f299337a28aa561409688a268d0efe6e295cgithub_commit Patch Available
commit e396a0a4b6b3 (wolfSSL/wolfssh)
Patch available: wolfSSL/wolfssh v1.6.0-stable (contains commit e396a0a4b6b3)
https://github.com/wolfSSL/wolfssh/commit/e396a0a4b6b367f10270287446a4be0071742b5cgithub_commit Patch Available
commit 616eb681e707 (wolfSSL/wolfssh)
Patch available: wolfSSL/wolfssh v1.6.0-stable (contains commit 616eb681e707)
https://github.com/wolfSSL/wolfssh/commit/616eb681e70759c30c3ba158f2b18d7bd954def8Vendor Advisories for CVE-2026-81535(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 10× in last 7d / 10× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-10-07 23:48 UTCEPSS rescore
- 2026-10-07 19:21 UTCEG score recompute
- 2026-10-07 19:21 UTCGHSA enrichment
- 2026-10-07 18:47 UTCEG score recompute
- 2026-10-07 18:47 UTCGHSA enrichment
- 2026-10-07 16:15 UTCGHSA enrichment
- 2026-10-07 03:31 UTCEG score recompute
- 2026-10-07 03:31 UTCGHSA enrichment
- 2026-10-07 02:47 UTCEG score recompute
- 2026-10-07 02:46 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-81535?
CVE-2026-81535 is a medium vulnerability published on October 7, 2026. 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…
When was CVE-2026-81535 disclosed?
CVE-2026-81535 was first published on October 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81535 actively exploited?
CVE-2026-81535 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (18th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-81535?
CVE-2026-81535 has a CVSS base score of 6.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-81535?
A fix for CVE-2026-81535 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-81535 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-81535
Is Your Infrastructure Affected by CVE-2026-81535?
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