CVE-2025-5777: NetScaler ADC and NetScaler Gateway - Insufficient input validation leading to memory overread
Noroxi assessment
Priority: Now (action score 97/100)
- CISA has confirmed exploitation in the wild (Jul 10, 2025); it is known to be used in ransomware campaigns. Remediation deadline for US federal agencies: Jul 11, 2025.
- A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
- Probability of exploitation in the next 30 days: 99.9% (FIRST EPSS); higher than 99.9% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- According to CISA the attack is automatable: targets can be found by mass scanning.
- Fixed version: NetScaler ADC 43.56, 58.32; NetScaler Gateway 43.56, 58.32.
Patch today or shut off access. Upgrade to NetScaler ADC 43.56, 58.32; NetScaler Gateway 43.56, 58.32 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS
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
- Published
- Jun 17, 2025
- Updated
- Oct 8, 2026
- EPSS
- 99.9% · 99th percentile
- CWE
- CWE-125
Report tools
Action score
97
Now
Patch today or shut off access.
- CVSS
- 37 / 40 · 9.3 / 10
- CISA KEV
- 30 / 30 · Listed
- EPSS
- 30 / 30 · 99.9%
CISA SSVC decision
- Exploitation
- active
- Automatable
- yes
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · Citrix
- 9.3
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Actively exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on Jul 10, 2025. That signals real attacks, not theory.
Remediation deadline for US federal agencies: Jul 11, 2025.
Known to be used in ransomware campaigns.
Get told when this record changes
- In CISA KEV: exploitation in the wild confirmed
- Weaponized exploit exists
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| citrix | netscaler application delivery controller | cpe:2.3:a:citrix:netscaler_application_delivery_controller |
| citrix | netscaler gateway | cpe:2.3:a:citrix:netscaler_gateway |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- citrix netscaler application delivery controller12.1 and later · before 12.1-55.328
- citrix netscaler application delivery controller13.1 and later · before 13.1-37.235
- citrix netscaler application delivery controller13.1 and later · before 13.1-58.32
- citrix netscaler application delivery controller14.1 and later · before 14.1-43.56
- citrix netscaler gateway13.1 and later · before 13.1-58.32
- citrix netscaler gateway14.1 and later · before 14.1-43.56
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Citrix). Independent of NVD's CPE analysis and usually ahead of it.
NetScaler ADC
- 14.1 and later · before 43.56affected · patch
- 13.1 and later · before 58.32affected · patch
NetScaler Gateway
- 14.1 and later · before 43.56affected · patch
- 13.1 and later · before 58.32affected · patch
Same product
citrix: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-3519Unauthenticated remote code executionKEV99Now
- CVE-2026-3055Insufficient input validation leading to memory overreadKEV94Now
- CVE-2026-88771A remote code execution vulnerability exists due to improper input validation, which can allow an unauthenticated attacker to execute arbitrary commandsKEV93Now
Published before and after this one in the same product
- ← EarlierCVE-2024-8535Nov 12, 2024 · Authenticated user can access unintended user capabilities23Monitor
- ← EarlierCVE-2025-5349Jun 17, 2025 · NetScaler ADC and NetScaler Gateway - Improper access control on the NetScaler Management Interface36Monitor
- Later →CVE-2025-6543Jun 25, 2025 · Memory overflow vulnerability leading to unintended control flow and Denial of ServiceKEV69This week
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| NetScaler ADC | 43.56 | Vendor (CNA) |
| NetScaler ADC | 58.32 | Vendor (CNA) |
| NetScaler Gateway | 43.56 | Vendor (CNA) |
| NetScaler Gateway | 58.32 | Vendor (CNA) |
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Exploit-DB entry ×1
- Nuclei detection template ×1
- Proof-of-concept repository on GitHub ×26
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Exploit-DB entry | remote | 2025-08-11 |
| Nuclei detection template | Nuclei template CVE-2025-5777 | — |
| Proof-of-concept repository on GitHub | stars:17 | 2025-06-30 |
| Proof-of-concept repository on GitHub | stars:1 | 2025-07-04 |
| Proof-of-concept repository on GitHub | stars:0 | 2025-07-05 |
| Proof-of-concept repository on GitHub | stars:3 | 2025-07-05 |
| Proof-of-concept repository on GitHub | stars:0 | 2025-07-06 |
| Proof-of-concept repository on GitHub | stars:2 | 2025-07-06 |
| Proof-of-concept repository on GitHub | stars:7 | 2025-07-08 |
| Proof-of-concept repository on GitHub | stars:50 | 2025-07-08 |
| Proof-of-concept repository on GitHub | stars:0 | 2025-07-09 |
| Proof-of-concept repository on GitHub | stars:31 | 2025-07-10 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- First PoC+12 d
- CISA KEV+22 d
- TodayOct 31, 2026+501 d
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-3055279 days apartInsufficient input validation leading to memory overreadKEV94Now
- CVE-2026-8451378 days apartInsufficient input validation leading to memory overread35Monitor
- CVE-2026-10817378 days apartInsufficient input validation leading to memory overread27Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-125 · Out-of-bounds ReadCVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (9 more)Show less
- citrixbleed.com
- horizon3.ai/attack-research/attack-blogs/cve-2025-5777-citrixbleed-2-write-up-maybe/
- labs.watchtowr.com/how-much-more-must-we-bleed-citrix-netscaler-memory-disclosure-citrixbleed-2-cve-2025-5777/
- www.bleepingcomputer.com/news/security/cisa-tags-citrix-bleed-2-as-exploited-gives-agencies-a-day-to-patch/
- www.netscaler.com/blog/news/netscaler-critical-security-updates-for-cve-2025-6543-and-cve-2025-5777/
- www.theregister.com/2025/07/10/cisa_citrixbleed_kev/
- doublepulsar.com/citrixbleed-2-exploitation-started-mid-june-how-to-spot-it-f3106392aa71
- reliaquest.com/blog/threat-spotlight-citrix-bleed-2-vulnerability-in-netscaler-adc-gateway-devices/
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-5777
Vendor advisories and official records. Exploit/PoC links are deliberately left out.