CVE-2025-5777
Confirmed PUBLISHEDNetScaler ADC and NetScaler Gateway - Insufficient input validation leading to memory overread
1 day faster than CISA KEV
Recommended Action
Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment.
At a Glance
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
- CVE Published
- Jun 17, 2025
- Exploitation Reported
- Jun 01, 2026
- CVSS
- 9.3 Critical
- EPSS
- 99.9%
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| NetScaler |
ADC
|
14.1 to < 43.56 |
Affected |
| NetScaler |
ADC
|
13.1 to < 58.32 |
Affected |
| NetScaler |
Gateway
|
14.1 to < 43.56 |
Affected |
| NetScaler |
Gateway
|
13.1 to < 58.32 |
Affected |
CVE References
- support.citrix.com/support-home/kbsearch/article support.citrix.com · CVE Record https://support.citrix.com/support-home/kbsearch/article?articleNumbe...
Recommended Actions
- Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment.
- Review sensor telemetry for request paths, attacker IPs, and payload patterns that may inform detection and exposure validation.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| The Shadowserver First | 2026-06-01 00:00 UTC |
| CVE | 2026-06-01 10:36 UTC |
| CISA | 2026-06-02 14:07 UTC |
| KEVIntel | 2026-07-01 08:30 UTC |
| TheHackerNews | 2026-07-02 20:20 UTC |
Operational indicators for this CVE are listed on the Detection tab.
Observed Exploitation Attempts
Exploitation attempts against this vulnerability observed first-hand by KEVIntel private honeypots over the last 30 days.
- Attempts Observed
- 6
- Unique Attacker IPs
- 3
- Attacker Countries
- 🇦🇺 🇺🇸
- Sensors Observed
- 2
Exploitation Attempts Over the Last 20 Days
First observed (all time) 2026-07-01 07:49 UTC · Last observed 2026-07-07 03:30 UTC
See more exploitation detail
- Pro — sensor software/region breakdown and 24h/7d window summaries.
- Enterprise — raw attacker IPs, request paths, User-Agents, and payloads.
Indicators of Compromise (IoCs)
Attacker IP IoCs observed in KEVIntel sensors are available to Pro and Enterprise accounts on the Detection tab and through the Pro API.
Learn about Pro API accessObserved Detection Signals (30d)
Aggregate counts from KEVIntel sensor telemetry for this CVE.
- Distinct request paths
- 1
- Distinct User-Agents
- 3
The specific request paths and User-Agents attackers are using are available on Pro and Enterprise plans.
Scanner Artifacts
Nuclei and Metasploit references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-5777.yaml | Jun 01, 2026 |
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
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
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Exploitation Status
Exploited in the wild
Recorded 2026-06-01 10:36:46 UTC · CVE
Active exploitation observed
Recorded 2026-06-27 10:21:25 UTC · KEVIntel sensor
Used in malware
Recorded 2026-06-02 14:07:05 UTC · CVE
Proof of concept available
Recorded 2026-06-12 14:21:09 UTC · Nuclei Templates
Weaknesses (CWE)
-
Out-of-bounds Read
-
Use of Uninitialized Variable
-
Use of Uninitialized Resource
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-5777.yaml | Jun 01, 2026 |
Recent Mentions
Huntress Blog · Jul 09, 2026
Huntress has observed a series of strikingly similar intrusions beginning with CitrixBleed 2 exploitation, employing novel local privilege escalation techniques, and ending in Dragonforce ransomware.
TheHackerNews · Jul 02, 2026
Threat actors associated with the Anubis ransomware operation have been observed exploiting the Citrix Bleed 2 (CVE-2025-5777) vulnerability to obtain initial access. "Although tactics differ between affiliates, common patterns emerged in tradecraft through use of legitimate Remote Management and Monitoring (RMM) tooling, credential access, and hands-on-keyboard procedures used for lateral
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
nuclei · Created Unknown
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
20:20 UTC 17 days ago20:20 UTC · 17 days ago
KEV confirmed by TheHackerNews
Exploitation attested by an external source
-
10:21 UTC 22 days ago10:21 UTC · 22 days ago
Observed by KEVIntel sensors
Evidence-backed exploitation signal
-
10:21 UTC 22 days ago10:21 UTC · 22 days ago
Indicators of compromise added (19)
Indicators of compromise recorded
-
14:21 UTC about 1 month ago14:21 UTC · about 1 month ago
Public PoC available
Public proof-of-concept code published
-
14:07 UTC about 2 months ago14:07 UTC · about 2 months ago
First public exploitation report
Exploit observed in malware
-
14:07 UTC about 2 months ago14:07 UTC · about 2 months ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
15:34 UTC about 2 months ago15:34 UTC · about 2 months ago
Nuclei template available
Scanner coverage available
-
10:36 UTC about 2 months ago10:36 UTC · about 2 months ago
KEV confirmed by CVE
Exploitation attested by an external source
-
00:00 UTC about 2 months ago00:00 UTC · about 2 months ago
Added to KEVIntel KEV Feed
High-confidence, third-party attested exploitation
-
12:29 UTC about 1 year ago12:29 UTC · about 1 year ago
CVE published
Vulnerability disclosed publicly
-
06:14 UTC about 1 year ago06:14 UTC · about 1 year ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2025-5777
{
"cve_id": "CVE-2025-5777",
"title": "NetScaler ADC and NetScaler Gateway - Insufficient input validation leading t...",
"affected_vendor": "NetScaler",
"affected_product": "ADC, Gateway",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 9.3,
"epss_score": 0.9987,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": true
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}