CVE-2025-5777
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
do firstApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Can a WAF block it? Partly. Cloudflare publishes WAF a rule written for this CVE. Such rules block the known exploit requests and buy time, but attackers can change the request to get past them, so they do not replace the patch.
Cloudflare · 1 rule (Disabled) · since 21 Jul 2025
- Citrix Netscaler ADC - Buffer Error - CVE:CVE-2025-5777 · Cloudflare Managed Ruleset
Also consider: patch · enable the vendor rule in block mode
Based on WAF vendor rules published for this CVE. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Is CVE-2025-5777 being exploited?
Yes. CVE-2025-5777 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2025-5777?
CVE-2025-5777 is rated High with a CVSS score of 7.5. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2025-5777?
Yes. A fix has been recorded for CVE-2025-5777. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2025-5777 affect?
CVE-2025-5777 affects citrix:netscaler_application_delivery_controller, citrix:netscaler_gateway. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
- affected>= 14.1 and < 43.56
- affected>= 13.1 and < 58.32
- affected>= 14.1 and < 43.56
- affected>= 13.1 and < 58.32
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
public exploits
Public exploit code: 1 on Exploit-DB · 26 GitHub proofs of concept · 1 Nuclei template
- Citrix NetScaler ADC/Gateway 14.1 - Memory Disclosure · remote · 11 Aug 2025
- Citrix NetScaler Memory Disclosure - CitrixBleed 2 · detection template · critical
- win3zz/CVE-2025-5777 · 50 ★
- bughuntar/CVE-2025-5777 · 31 ★
- mingshenhk/CitrixBleed-2-CVE-2025-5777-PoC- · 17 ★
- Chocapikk/CVE-2025-5777 · 7 ★
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
cisa ssvc
- exploitation
- active
- automatable
- yes
- technical impact
- total
Assessed by CISA 4 Aug 2026 (SSVC 2.0.3).
timeline
- 17 Jun 2025Published
- 30 Jun 2025First public exploit or proof of concept · 12 days later
- 10 Jul 2025Added to CISA KEV (exploited in the wild) · 10 days later
- 11 Jul 2025CISA remediation due date (US federal agencies) · 1 day later
- 4 Aug 2026CISA SSVC assessment: exploitation active · 389 days (about 1 year) later
- 7 Oct 2026CVE record last updated · 65 days (about 2 months) later
- 2 Nov 2026Analysed by vulneraibility.com · 26 days later
- Advisorydoublepulsar.com /citrixbleed-2-exploitation-started-mid-june-how-to-spot-it-f3106392aa71
- Linksupport.citrix.com /support-home/kbsearch/article?articleNumber=CTX693420
- Linkreliaquest.com /blog/threat-spotlight-citrix-bleed-2-vulnerability-in-netscaler-adc-gateway-dev
- Linkcisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-5777
- Linkbleepingcomputer.com /news/security/cisa-tags-citrix-bleed-2-as-exploited-gives-agencies-a-day-to-pat
- Linklabs.watchtowr.com /how-much-more-must-we-bleed-citrix-netscaler-memory-disclosure-citrixbleed-2-cv
- Linktheregister.com /2025/07/10/cisa_citrixbleed_kev/
- Linkhorizon3.ai /attack-research/attack-blogs/cve-2025-5777-citrixbleed-2-write-up-maybe/
Show 2 more
- Linknetscaler.com /blog/news/netscaler-critical-security-updates-for-cve-2025-6543-and-cve-2025-57
- Linkcitrixbleed.com
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Exploit-DB: published exploits
- Nuclei templates: detection templates
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.