Evidence dossier

CVE-2026-88779

Memory overflow vulnerability leading to Denial of Service

Exploited in the wild (CISA KEV since Oct 4, 2026). NetScaler reports CVSS 4.0 8.7. EPSS estimates 0.6% exploit likelihood as of Oct 22, 2026.

63.3–72.1Priority evidence range
Evidence through Oct 22, 2026, 6:07 PM UTC

As of Oct 22, 2026

Normalized restatement

Vulnerability in NetScaler ADC and NetScaler Gateway. This issue affects ADC: before 14.1-73.41, before 13.1-64.28, before 14.1-73.41 FIPS, and before 13.1-37.282; Gateway: before 14.1-73.41 and before 13.1-64.28.

State
PUBLISHED
Published
Oct 4, 2026
Updated
Oct 5, 2026
Evidence coverage
85%

Evidence chronology

What was known when

Download this view's receipt →
  1. Source dateSource date omittedFirst observed by CASCA
    CISA-ADP

    Record text: CISA ADP Vulnrichment

    Inspect raw assertion
    Field
    container
    Value
    CISA ADP Vulnrichment
    Original evidence ↗
  2. Source dateSource date omittedFirst observed by CASCA
    NetScaler

    Record text: Memory overflow vulnerability leading to Denial of Service

    Inspect raw assertion
    Field
    container
    Value
    Memory overflow vulnerability leading to Denial of Service
    Original evidence ↗
  3. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 0.59% probability · 47.59th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.005920000000; percentile 0.475900000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Oct 4, 2026 · first observed Oct 9, 2026

Exploit likelihood0.59%

FIRST EPSS · score date Oct 22, 2026 · 47.6th percentile · first observed Oct 22, 2026

SeverityCVSS 8.7

NetScaler · CVSS 4.0 · first observed Oct 5, 2026 · same-version scores align in this snapshot

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusLast verified source snapshot retained

The last verified source boundary remains in force for this claim.

Revision
evidence-policy-v1.1.0
Cutoff
Oct 22, 2026
Resolution
Review source contract
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Oct 22, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Oct 22, 2026
Resolution
None
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Oct 22, 2026
Resolution
Resolve identity

Source comparison

Who said what

CISA-ADPIndependent enrichment
Record text

CISA ADP Vulnrichment

Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
NetScalerOriginal assertion
Record text

Memory overflow vulnerability leading to Denial of Service

Inspect raw assertion
Field
container
Value
Memory overflow vulnerability leading to Denial of Service
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Citrix NetScaler Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

0.59% probability · 47.59th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.005920000000; percentile 0.475900000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →

9 scope groups

NetScaler · source assertedNetScalerADCDirect source scope
Affected: 0 to before 14.1-73.41 (Patch comparison)Affected: 0 to before 13.1-64.28 (Patch comparison)Affected: 0 to before 14.1-73.41 FIPS (Patch comparison)Affected: 0 to before 13.1-37.282 (Patch comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "0", "lessThan": "14.1-73.41", "versionType": "Patch"}, {"status": "affected", "version": "0", "lessThan": "13.1-64.28", "versionType": "Patch"}, {"status": "affected", "version": "0", "lessThan": "14.1-73.41 FIPS", "versionType": "Patch"}, {"status": "affected", "version": "0", "lessThan": "13.1-37.282", "versionType": "Patch"}]
NetScaler · source assertedNetScalerGatewayDirect source scope
Affected: 0 to before 14.1-73.41 (Patch comparison)Affected: 0 to before 13.1-64.28 (Patch comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "0", "lessThan": "14.1-73.41", "versionType": "Patch"}, {"status": "affected", "version": "0", "lessThan": "13.1-64.28", "versionType": "Patch"}]
NVD · source assertedVendor unspecified by sourceProduct unspecified by sourceDirect source scope
Version bounds not stated
Scope supported
Inspect raw assertioncpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:*; start including 13.1; end excluding 13.1-64.28
NVD · source assertedVendor unspecified by sourceProduct unspecified by sourceDirect source scope
Version bounds not stated
Scope supported
Inspect raw assertioncpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:*; start including 14.1; end excluding 14.1-73.41
NVD · source assertedVendor unspecified by sourceProduct unspecified by sourceDirect source scope
Version bounds not stated
Scope supported
Inspect raw assertioncpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:*; start including 13.1; end excluding 13.1-37.282
NVD · source assertedVendor unspecified by sourceProduct unspecified by sourceDirect source scope
Version bounds not stated
Scope supported
Inspect raw assertioncpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:*; start including 14.1-66.68; end including 14.1-73.41
NVD · source assertedVendor unspecified by sourceProduct unspecified by sourceDirect source scope
Version bounds not stated
Scope supported
Inspect raw assertioncpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:ndcpp:*:*:*; start including 13.1; end excluding 13.1-37.282
NVD · source assertedVendor unspecified by sourceProduct unspecified by sourceDirect source scope
Version bounds not stated
Scope supported
Inspect raw assertioncpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*; start including 13.1; end excluding 13.1-64.28
NVD · source assertedVendor unspecified by sourceProduct unspecified by sourceDirect source scope
Version bounds not stated
Scope supported
Inspect raw assertioncpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*; start including 14.1; end excluding 14.1-73.41

Affected-product evidence

Accepted scope and product mapping

0 canonical links · 2 source-reported links

Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Direct cve affected
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Oct 22, 2026
Retained assertion IDs
27eb454b-2536-4b20-8326-b0b650cd88136f933307-e630-4d6e-862e-e9706764b857
Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Nvd cpe vulnerable target
Assertions
7
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Oct 22, 2026
Retained assertion IDs
0d4f4de0-5298-4780-b310-96b3bd994766376431de-b613-4312-b0f9-27d94df112554474c84f-1f93-4e5c-9de5-29106930547b45449329-9b00-49e4-9f0c-c8f5347f65a069fc8e7c-79e1-4f0b-b6d4-4405915fc4f5d75ed29c-6642-4052-8bde-4c1e3c1836d5f47cbe8f-910b-45e8-a8fe-1d22b79c2e0e

Assessments

CVSS by origin

7.5
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7
CVE Program sourceCVSS 4.0 · role Secondary · priority eligiblevalid_matchCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/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
8.7
NetScalerCVSS 4.0 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Direct CVE/CNA normalized decisions

8.7Priority eligible

NetScaler

CVSS 4.0 · Primary · Original assertion · rank 1

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Validation
Valid match
Recomputed
8.7
Decision reason
Evidence supported
Policy
casca-direct-cvss-eligibility-v1

Assessments are retained side by side under closed precedence. Cascade never averages CVSS.

Evidence boundaries

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; remaining scope stays source-scoped.
  • NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
  • OSV aggregation and OSV-converted NVD material are not independent corroboration.
  • Red Hat facts are vendor assertions for the exact supplied products.
  • Nonmembership and not-yet-observed states are not proof of safety.