KEV Intelligence

Vulnerability report

Active exploitation observed Confirmed confidence Not in CISA KEV

CVE-2026-8451

Insufficient input validation leading to memory overread

NetScaler / ADC · affected before 72.61

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Severity
CVSS 8.8 · High
Confidence
Confirmed
Exploit status
Observed in sensors
EPSS
15.7%
First observed
05 Jul 2026
Last observed
14 Aug 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-8451 is an unauthenticated Insufficient input validation leading to memory overread affecting NetScaler ADC, Gateway.

Is it exploited?

Yes. KEV Intelligence sensors observed exploitation attempts with confirmed confidence.

Who is affected?

NetScaler / ADC affected before 72.61.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

Insufficient input validation leading to memory overread

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

Vendor Product Affected Status
NetScaler ADC Before 72.61 Affected
NetScaler ADC Before 63.18 Affected
NetScaler ADC Before 72.61 Affected
NetScaler ADC Before 37.272 Affected
NetScaler Gateway Before 72.61 Affected
NetScaler Gateway Before 63.18 Affected
Published
30 Jun 2026
Exploitation Reported
01 Jul 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

CVE References

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

Lupovis

Recorded 01 Jul 2026

Independent exploitation attestation added to the KEV Intelligence record.

Active exploitation observed

KEV Intelligence sensor

First observed 05 Jul 2026

First-party sensor telemetry confirms matching exploitation attempts.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source Added
Lupovis First 2026-07-01 21:50 UTC
KEV Intelligence 2026-07-02 16:56 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Aggregate observations show the scale, recency, and distribution of activity without overstating sparse data.

1

Attempts observed

1

Unique attacker IPs

1

Attacker countries

PA

1

Sensors observed

Exploitation attempts over the last 45 days

Daily events observed by KEV Intelligence sensors

Updated 17 Aug 2026

0
52
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0
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0
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0
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4 Jul 13 Jul 22 Jul 31 Jul 17 Aug

First observed 05 Jul 2026 · Last observed 14 Aug 2026

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Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
1
User-Agents
1

Raw values available in Pro and Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

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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 about 2 months ago Source

Risk and context

Severity, weaknesses, and research context

CVSS v4.0

8.8 High
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

EPSS

15.7%

Weaknesses

Out-of-bounds Read CWE-125

Recent mention · TheHackerNews

Citrix Patches Six NetScaler Flaws Allowing File Read and Denial-of-Service

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)...

Read full advisory

All CVSS Scores

CVSS v4.0 8.8 High

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 v3.1 7.5 High

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

All Mentions

Recent mention · TheHackerNews

Citrix Patches Six NetScaler Flaws Allowing File Read and Denial-of-Service

TheHackerNews · 01 Jul 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

Recent mention · Watchtower Labs

CitrixBleed To Infinity And Beyond (Citrix NetScaler Pre-Auth Memory Overread CVE-2026-8451)

Watchtower Labs · 30 Jun 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

Timeline

From disclosure to observed exploitation

  1. Observed by KEV Intelligence sensors

    Evidence-backed exploitation signal

  2. Added to KEV Intelligence KEV Feed

    High-confidence, third-party attested exploitation

  3. Indicators of compromise added (3)

    Indicators of compromise recorded

  4. CVE published

    Vulnerability disclosed publicly

  5. CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-8451

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2026-8451",
  "confidence": "Confirmed",
  "cvss_score": 8.8,
  "epss_score": 0.15654,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 1, "sensors": 1 }
}

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