The Sequels Are Never As Good, But We're Still In Pain (Citrix NetScaler CVE-2026-3055 Memory Overread)

Sicherheitsmeldung mit Schweregrad mittel (CVSS 4.0). Sie wird laut CISA-KEV aktiv ausgenutzt und sollte priorisiert behandelt werden. Betroffene Kennungen: CVE-2025-12101, CVE-2025-5777, CVE-2026-3055. Technische Details im Tab „Originaltext“; empfohlene Schritte in der Checkliste.

Originaltext der Quelle (nicht übersetzt) – die deutsche Zusammenfassung findest du im Tab „Kurzfassung".

Sequels? Pain? We're obviously talking about Citrix NetScalers, yet again.Welcome back to another watchTowr Labs blog post - pull up a chair, we always welcome new members to our group therapy sessions.If you asked a C programmer what they most dislike doing in life, their answer might well be:Using an IDE,Constantly rejecting job offers to work on Citrix NetScalers,Writing C instead of Assembly, and,Writing string processing code in C.While C is to some a glorious and beautiful language (as every parent believes their child is the most beautiful), it is (like said children) simply not well-suited for string processing.Unfortunately, we're back with another example - in the form of the recently disclosed Citrix NetScaler CVE-2026-3055. Described as a 'memory overread' vulnerability, many would've read the words and screamed.Why? Because this sounds suspiciously similar to CitrixBleed and CitrixBleed2, which continue to represent a trauma event for many.CitrixBleed, the first in the series, is infamous both because it was a serious vulnerability that allowed the disclosure of memory and subsequent remote-access session hijacking, and because, years later, we are still reeling from the aftermath of the prolific exploitation it received.Then, CitrixBleed2 made headlines in 2025, where we (watchTowr) publicly shared concerns within our analysis about the repetition and Ground Hog Day-esque world we seem to live in.You may also remember that in 2025, we disclosed further memory overread (unrealistic, unlikely to exist in the real-world) vulnerabilities within fully patched …

Vollständiger Originalartikel ↗

• Betroffenheit im eigenen Stack prüfen (CVE-2025-12101, CVE-2025-5777, CVE-2026-3055): Versionen/Komponenten abgleichen.
• Originalquelle / Hersteller-Advisory lesen: https://labs.watchtowr.com/the-sequels-are-never-as-good-but-were-still-in-pain-citrix-netscaler-cve-2026-3055-memory-overread/
• Priorität HOCH: laut CISA-KEV aktiv ausgenutzt – bevorzugt patchen.
• Verfügbaren Patch oder Workaround einspielen und dokumentieren.