ZDI-26-590: libwebsockets HTTP/2 HPACK Path Header Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability
ZDI disclosed CVE-2026-19773, an unauthenticated out-of-bounds write allowing remote code execution in libwebsockets HTTP/2 HPACK parsing, rated CVSS 9.8.
The Zero Day Initiative published advisory ZDI-26-590 for an out-of-bounds write vulnerability in libwebsockets' HTTP/2 HPACK path header parsing. A remote attacker can execute arbitrary code on affected installations without authentication. The flaw is tracked as CVE-2026-19773 and carries a CVSS score of 9.8.
ZDI-26-533: Cisco Secure Firewall Management Center login.cgi Authentication Bypass Vulnerability
ZDI discloses CVE-2026-20316, a 9.8-rated unauthenticated authentication bypass in Cisco Secure Firewall Management Center login.cgi.
ZDI-26-533 describes an authentication bypass vulnerability in Cisco Secure Firewall Management Center's login.cgi that allows remote attackers to bypass authentication without any credentials. ZDI assigned a CVSS score of 9.8, and the flaw is tracked as CVE-2026-20316. As a central management plane for firewall infrastructure, compromise could enable broad policy changes.
Microsoft’s Biggest Patch Tuesday: 974 CVEs, 2 Zero-Days and 20 Wormable Bugs
Microsoft's record September 2026 Patch Tuesday fixes 974 CVEs, including two exploited Windows privilege-escalation zero-days and 20 wormable bugs.
Microsoft's September 2026 Patch Tuesday fixes a record 974 CVEs, including two actively exploited zero-days: CVE-2026-85880, an ALPC heap buffer overflow, and CVE-2026-81963 in the Windows Update Stack, both CVSS 7.8 local privilege escalations. It also addresses an unauthenticated Exchange RCE (CVE-2026-55007) triggered by Visio attachment content indexing under memory pressure, an RDP use-after-free (CVE-2026-69525, CVSS 9.8), and 20 wormable flaws in DNS, DHCP, SMB, Active Directory, and other components. ZDI attributed the rising volume partly to AI-assisted vulnerability discovery, noting no corresponding spike in active exploits yet.