CVE-2026-8451
Confirmed PUBLISHEDInsufficient input validation leading to memory overread
Not yet in 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 in NetScaler ADC and NetScaler Gateway leading to memory overread if NetScaler ADC or NetScaler Gateway is configured as a SAML IDP
- CVE Published
- Jun 30, 2026
- Exploitation Reported
- Jul 01, 2026
- CVSS
- 8.8 High
- EPSS
- 0.5%
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| NetScaler |
ADC
|
14.1 to < 72.61 |
Affected |
| NetScaler |
ADC
|
13.1 to < 63.18 |
Affected |
| NetScaler |
ADC
|
14.1 FIPs to < 72.61 |
Affected |
| NetScaler |
ADC
|
13.1 FIPS and NDcPP to < 37.272 |
Affected |
| NetScaler |
Gateway
|
14.1 to < 72.61 |
Affected |
| NetScaler |
Gateway
|
13.1 to < 63.18 |
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 |
|---|---|
| Lupovis First | 2026-07-01 21:50 UTC |
| KEVIntel | 2026-07-02 16:56 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
- 52
- Unique Attacker IPs
- 1
- Attacker Countries
- 🇳🇱
- Sensors Observed
- 1
Exploitation Attempts Over the Last 16 Days
First observed (all time) 2026-07-05 20:47 UTC · Last observed 2026-07-05 20:47 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)
Operational indicators linked to exploitation of this CVE. IoCs age over time — especially IP addresses.
| Type | Indicator | First Seen | Last Seen | Age | Source |
|---|---|---|---|---|---|
| IP |
146.70.139.154
|
2026-07-01 21:50 UTC | 2026-07-01 21:50 UTC | 17 days ago | Source |
Observed Detection Signals (30d)
Aggregate counts from KEVIntel sensor telemetry for this CVE.
- Distinct request paths
- 1
- Distinct User-Agents
- 1
The specific request paths and User-Agents attackers are using are available on Pro and Enterprise plans.
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:L/VA:H/SC:N/SI:N/SA:N
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 2026-07-01 21:50:00 UTC · Lupovis
Active exploitation observed
Recorded 2026-07-05 20:47:07 UTC · KEVIntel sensor
Proof of concept available
Recorded 2026-06-30 15:28:14 UTC · GitHub
Weaknesses (CWE)
-
Out-of-bounds Read
Recent Mentions
TheHackerNews · Jul 01, 2026
Citrix on Tuesday released security updates to address multiple flaws in NetScaler ADC (formerly Citrix ADC) and NetScaler Gateway (formerly Citrix Gateway) that could be exploited by an attacker to facilitate arbitrary file reads or trigger a denial-of-service (DoS) condition. The vulnerabilities are listed below - CVE-2026-8451 (CVSS score: 8.8) - An insufficient input validation
Watchtower Labs · Jun 30, 2026
Well, well, well - once again, the cat has dragged us in and spat us out.Today, we find ourselves questioning the reality we sit within. Must it be so predictable, and why us? “But watchTowr, what do you mean?”Well, if you’re here, you likely fit
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2026-07-07 23:52:08 UTC · 0 stars
CVE-2026-8451 - Citrix NetScaler SAML Memory Overread (CitrixBleed) - PoC & Analysis | CVSS 8.8 | AMN SECURITY
github · Created 2026-07-02 03:53:48 UTC · 0 stars
github · Created 2026-06-30 15:28:14 UTC · 2 stars
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
20:47 UTC 14 days ago20:47 UTC · 14 days ago
Observed by KEVIntel sensors
Evidence-backed exploitation signal
-
21:50 UTC 17 days ago21:50 UTC · 17 days ago
Added to KEVIntel KEV Feed
High-confidence, third-party attested exploitation
-
21:50 UTC 17 days ago21:50 UTC · 17 days ago
Indicators of compromise added (2)
Indicators of compromise recorded
-
15:28 UTC 19 days ago15:28 UTC · 19 days ago
Public PoC available
Public proof-of-concept code published
-
12:33 UTC 19 days ago12:33 UTC · 19 days ago
CVE published
Vulnerability disclosed publicly
-
00:35 UTC 2 months ago00:35 UTC · 2 months 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-2026-8451
{
"cve_id": "CVE-2026-8451",
"title": "Insufficient input validation leading to memory overread",
"affected_vendor": "NetScaler",
"affected_product": "ADC, Gateway",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 8.8,
"epss_score": 0.00502,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": true
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}