CVE-2025-5777

Citrix NetScaler ADC and Gateway Out-of-Bounds Read

7.5 HIGHActively exploited (CISA KEV)Used in ransomwareEPSS 100.0%

Published17 Jun 2025
Added to CISA KEV10 Jul 2025
Remediation due11 Jul 2025

Description

Insufficient input validation leading to memory overread when the NetScaler is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityNone

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

Citrix NetScaler Application Delivery Controller≥ 13.1 < 13.1-58.32 · ≥ 14.1 < 14.1-43.56 · ≥ 12.1 < 12.1-55.328 · ≥ 13.1 < 13.1-37.235

Citrix NetScaler Gateway≥ 13.1 < 13.1-58.32 · ≥ 14.1 < 14.1-43.56

Remediation

Fixed in

Citrix NetScaler Application Delivery Controller≥ 13.1-58.32

Citrix NetScaler Gateway≥ 13.1-58.32

Patch & vendor advisories

https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX693420

References

https://citrixbleed.comBroken LinkThird Party Advisory
https://doublepulsar.com/citrixbleed-2-exploitation-started-mid-june-how-to-spot-it-f3106392aa71Third Party Advisory
https://horizon3.ai/attack-research/attack-blogs/cve-2025-5777-citrixbleed-2-write-up-maybe/Third Party Advisory
https://labs.watchtowr.com/how-much-more-must-we-bleed-citrix-netscaler-memory-disclosure-citrixbleed-2-cve-2025-5777/Third Party Advisory
https://reliaquest.com/blog/threat-spotlight-citrix-bleed-2-vulnerability-in-netscaler-adc-gateway-devices/Third Party Advisory
https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX693420Vendor Advisory
https://www.bleepingcomputer.com/news/security/cisa-tags-citrix-bleed-2-as-exploited-gives-agencies-a-day-to-patch/Press/Media CoverageThird Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-5777US Government Resource
https://www.netscaler.com/blog/news/netscaler-critical-security-updates-for-cve-2025-6543-and-cve-2025-5777/Third Party Advisory
https://www.theregister.com/2025/07/10/cisa_citrixbleed_kev/Press/Media Coverage

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2025-5777 being actively exploited?

Yes. CVE-2025-5777 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 10 Jul 2025. It has been used in ransomware campaigns.

How severe is CVE-2025-5777?

CVE-2025-5777 has a CVSS 3.1 base score of 7.5, rated high. EPSS estimates a 100.0% probability of exploitation.

Which products are affected by CVE-2025-5777?

Affected products include Citrix NetScaler Application Delivery Controller, Citrix NetScaler Gateway.

How do I fix CVE-2025-5777?

Upgrade affected software to a fixed version, for example Citrix NetScaler Application Delivery Controller 13.1-58.32, Citrix NetScaler Gateway 13.1-58.32 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2025-5777 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation works Book a demo

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.