Citrix NetScaler Pre-Auth RCE (CVE-2026-8452)
Unauthenticated heap overflow in SAML signature canonicalization. An oversized PrefixList inside the <ds:SignedInfo> InclusiveNamespaces element overflows a fixed-size buffer, corrupting adjacent nsb chunk metadata. This yields a write-what-where primitive (controlled memcpy src/dst), allowing overwrite of tx_pkt_complete_fptr and jump to attacker shellcode on the executable heap. Results in root RCE when NetScaler is configured as SAML SP or IdP.
Affected: NetScaler ADC/Gateway 14.1 < 14.1-72.61 and 13.1 < 13.1-63.18
Research:
https://labs.watchtowr.com/youre-back-in-the-room-citrix-netscaler-pre-auth-rce-cve-2026-8452/
Source:
https://github.com/watchtowrlabs/watchTowr-vs-Citrix-Netscaler-PreAuth-RCE-CVE-2026-8452
@IRCyberGuardians