{"id":"CVE-2026-91953","title":"FreeRDP versions before 3.31.0 contain a heap buffer overflow vulnerability in nego_send_negotiation_request() that fails to validate the LB_LOAD_BALANCE_INFO field length before writing to a fixed 512-byte buffer","summary":"FreeRDP versions before 3.31.0 contain a heap buffer overflow vulnerability in nego_send_negotiation_request() that fails to validate the LB_LOAD_BALANCE_INFO field length before writing to a fixed 512-byte buffer. A malicious RDP server…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","cwe":["CWE-120"],"vendor":"FreeRDP","product":"FreeRDP","affected":["FreeRDP < 3.31.0"],"published":"2026-09-15","updated":"2026-09-16","sourceUpdated":"2026-09-16T20:17:00.597","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-91953","references":[{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-r9pv-ffph-6gg6","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/freerdp-before-3.31.0-heap-buffer-overflow-via-lb-load-balance-info","label":"disclosure@vulncheck.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91953.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-91953"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2533959"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-91953"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-91953"}],"tags":["nvd","cve.org","exploit-available","csaf","vex","red-hat"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-15T16:01:12.250084Z"},"ingestedAt":"2026-09-15T15:39:12.919Z","epss":0.00422,"epssPercentile":0.36048,"slug":"CVE-2026-91953","body":"## Overview\n\nFreeRDP versions before 3.31.0 contain a heap buffer overflow vulnerability in nego_send_negotiation_request() that fails to validate the LB_LOAD_BALANCE_INFO field length before writing to a fixed 512-byte buffer. A malicious RDP server or man-in-the-middle can send a Server Redirection PDU with an oversized LB_LOAD_BALANCE_INFO value to overflow the buffer with attacker-controlled content, causing denial of service or heap corruption before authentication completes.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91953.json)","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":204278,"id":"CVE-2026-91953","ts":1789490443787,"field":"exploit_available","old":"false","new":"true"}]}