CVE Intelligence
Critical Memory corruption

CVE-2026-88776 — Memory overflow vulnerability leading to unpredictable or erroneous behavior or Denial of Service

Memory overflow vulnerability vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway. This issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS, and before 13.1.37.279 FIPS and NDcPP; Gateway: before 14.1-73.37 and before 13.1-64.23  leading to unpredictable or erroneous behavior or Denial of Service

Published Sep 27, 2026 · Updated Oct 16, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: NetScaler

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.4% (30-day exploitation probability)+5
  • Technical severity (critical)+10
  • Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.38%
ahead of 31% of scored CVEs · Oct 15, 2026
Affects
Citrix
Netscaler Application Delivery Controller and 3 more
CVSS base
9.8
Critical · 3 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Citrix Netscaler Application Delivery Controller, Citrix Netscaler Gateway, Citrix NetScaler ADC…).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Citrix Netscaler Application Delivery Controller ≥ 13.1 and < 13.1-64.23≥ 13.1 and < 13.1.37.279≥ 14.1 and < 14.1-73.37≥ 14.1-66.68 and ≤ 14.1-73.37 Vulnerable NIST National Vulnerability Database
Citrix Netscaler Gateway ≥ 13.1 and < 13.1-64.23≥ 14.1 and < 14.1-73.37 Vulnerable NIST National Vulnerability Database
Citrix NetScaler ADC < 14.1-73.37< 13.1-64.23< 14.1-73.37 FIPS< 13.1.37.279 FIPS and NDcPP Vulnerable CVE Program (cve.org) e CISA ADP
Citrix NetScaler Gateway < 14.1-73.37< 13.1-64.23 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
8.8 CVSS 4.0 High — — 50a63c94-1ea7-4568-8c11-eb79e7c5a2b5 via NIST National Vulnerability Database
8.8 CVSS 4.0 High — — NetScaler via CVE Program (cve.org) e CISA ADP
9.8 CVSS 3.1 Critical 3.9 5.9 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-119 · Buffer Errors (Improper Restriction of Operations within Memory Bounds)

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · citrix netscaler/adc, citrix netscaler/gateway
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 9.8
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Sep 27, 2026 · NetScaler

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

1 on the record

Elsewhere on this site

Citrix
every CVE for this vendor
Memory corruption
same class
CWE-119
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-88779 Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability KEV 12d
  • CVE-2026-88778 TCP Initial Sequence Number (ISN) prediction 18d
  • CVE-2026-88777 Memory overflow vulnerability leading to unpredictable or erroneous behavior or Denial of Service 18d
  • CVE-2026-88774 Feature policy bypass due to improper HTTP URL based expression usage 18d
  • CVE-2026-88775 Memory overflow vulnerability leading to unpredictable or erroneous behavior or Denial of Service 18d
  • CVE-2026-88773 HTTP Request Smuggling 18d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-88776 is "Memory overflow vulnerability leading to unpredictable or erroneous behavior or Denial of Service", rated Critical. It affects Netscaler Application Delivery Controller (Citrix); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. EPSS 0.38% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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