CVE-2026-81535

{"id": "CVE-2026-81535", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-81535", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-07T18:37:10.078645Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.2, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "facts@wolfssl.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 6.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "valueDensity": "NOT_DEFINED", "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "facts@wolfssl.com", "affectedData": [{"repo": "https://github.com/wolfSSL/wolfssh", "vendor": "wolfSSL Inc.", "modules": ["forwarding"], "product": "wolfSSH", "versions": [{"status": "affected", "changes": [{"at": "1.6.0", "status": "unaffected"}], "version": "1.4.8", "versionType": "semver", "lessThanOrEqual": "1.5.0"}], "programFiles": ["src/internal.c"], "defaultStatus": "unaffected"}]}], "published": "2026-10-07T03:16:59.567", "references": [{"url": "https://github.com/wolfSSL/wolfssh/commit/616eb681e70759c30c3ba158f2b18d7bd954def8", "tags": ["Patch"], "source": "facts@wolfssl.com"}, {"url": "https://github.com/wolfSSL/wolfssh/commit/79a7f299337a28aa561409688a268d0efe6e295c", "tags": ["Patch"], "source": "facts@wolfssl.com"}, {"url": "https://github.com/wolfSSL/wolfssh/commit/e396a0a4b6b367f10270287446a4be0071742b5c", "tags": ["Patch"], "source": "facts@wolfssl.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "facts@wolfssl.com", "description": [{"lang": "en", "value": "CWE-862"}, {"lang": "en", "value": "CWE-863"}]}], "descriptions": [{"lang": "en", "value": "In wolfSSH through 1.5.0 built with\u00a0--enable-fwd,\u00a0DoChannelOpen()\u00a0in\u00a0src/internal.c\u00a0gates only\u00a0direct-tcpip\u00a0channel opens with the forwarding policy callback.\u00a0forwarded-tcpip\u00a0opens 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\u00a0forwarded-tcpip\u00a0open against the forwards it registered with a\u00a0tcpip-forward\u00a0request, 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."}], "lastModified": "2026-10-13T17:36:15.900", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:wolfssh:wolfssh:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8CA7D4E4-4A1B-48B8-B749-1F504EB38148", "versionEndExcluding": "1.6.0"}], "operator": "OR"}]}], "sourceIdentifier": "facts@wolfssl.com"}