CVE-2026-88771

CRITICALNVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-09-27), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 9.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — KEV-added this weekExploited in the wild
9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • 1,489 internet-facing services (distinct ip:port) on record running an affected version — derived from Shodan data (© Shodan); a patched service can stay counted while its port stays open
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 1.1%CVSS: 9.8Exploit: cisa kev · ssvc active · public exploitExposed services: 1,489

A fix is available — apply it.

Improper input validation 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 an unauthenticated attacker to execute arbitrary commands.

Internet exposure · derived from Shodan data

1,489 internet-facing services (distinct ip:port) on record running a version that maps to CVE-2026-88771, in our KEV-Exposure radar’s Shodan-derived sample.

across 25 countries (Germany, Australia, United States, Mauritius, United Kingdom)top: netscaler_gateway
See the KEV-Exposure radar →Derived from Shodan data. Shodan data is owned by Shodan, which holds its copyright (© Shodan). EchelonGraph claims no ownership of it or copyright in it. Aggregate, host-redacted.

How it counts: every 12 hours, when Shodan query credits allow, the radar runs one Shodan query per tracked product, reads up to 100 ip:port services per query, and keeps a service when its banner version matches a CISA-KEV or high-EPSS CVE; a service is dropped when neither a search nor a Shodan InternetDB port re-check has refreshed it for 21 days. A re-check that finds the port still listed by Shodan InternetDB refreshes the service without re-reading the banner, so a patched service can stay counted while its port stays open. A count is a banner-version inference over a sample, not an exploit test and not an internet-wide census, and the unit is a service, not a machine: a machine answering on two ports counts twice.

CVSS v3
9.8
EG Score
9.8CRITICALhigh confidence
EG Risk
99
EG Risk 99/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation100% × 40%
Automatability100% × 15%
CISA SSVC: Attend at low mission impact; Act at medium or high.
Action: A fix is available. Apply it sooner than your standard update timelines at low mission impact and as soon as possible at medium or high.
EPSS PROB
1.1%
EPSS %ILE
63rd
KEV
⚠ Exploited

CISA SSVCAttend at low mission impact; Act at medium or high.

A fix is available. Apply it sooner than your standard update timelines at low mission impact and as soon as possible at medium or high.

Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 27, 2026

Last Modified

September 29, 2026

Advisory Details (2)

Auto-updated Sep 29, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-88771

Vendor Advisories for CVE-2026-88771(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 80× in last 7d / 80× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-04 10:31 UTCGHSA enrichment
  2. 2026-10-04 06:48 UTCGHSA enrichment
  3. 2026-10-04 03:06 UTCGHSA enrichment
  4. 2026-10-03 23:25 UTCGHSA enrichment
  5. 2026-10-03 19:43 UTCGHSA enrichment
  6. 2026-10-03 16:01 UTCEG score recompute
  7. 2026-10-03 16:00 UTCGHSA enrichment
  8. 2026-10-03 12:19 UTCGHSA enrichment
  9. 2026-10-03 08:36 UTCGHSA enrichment
  10. 2026-10-03 04:55 UTCGHSA enrichment
  11. 2026-10-03 01:13 UTCGHSA enrichment
  12. 2026-10-02 21:31 UTCEG score recompute
  13. 2026-10-02 21:31 UTCGHSA enrichment
  14. 2026-10-02 17:49 UTCGHSA enrichment
  15. 2026-10-02 14:07 UTCGHSA enrichment
  16. 2026-10-02 10:24 UTCGHSA enrichment
  17. 2026-10-02 06:43 UTCGHSA enrichment
  18. 2026-10-02 03:01 UTCGHSA enrichment
  19. 2026-10-01 23:16 UTCEG score recompute
  20. 2026-10-01 23:16 UTCGHSA enrichment
  21. 2026-10-01 19:51 UTCEPSS rescore
  22. 2026-10-01 19:34 UTCGHSA enrichment
  23. 2026-10-01 15:52 UTCGHSA enrichment
  24. 2026-10-01 12:10 UTCGHSA enrichment
  25. 2026-10-01 08:28 UTCGHSA enrichment
Show 55 more
  1. 2026-10-01 04:46 UTCGHSA enrichment
  2. 2026-10-01 01:01 UTCGHSA enrichment
  3. 2026-09-30 21:20 UTCGHSA enrichment
  4. 2026-09-30 17:38 UTCEG score recompute
  5. 2026-09-30 17:38 UTCGHSA enrichment
  6. 2026-09-30 15:04 UTCEPSS rescore
  7. 2026-09-30 13:56 UTCGHSA enrichment
  8. 2026-09-30 10:15 UTCGHSA enrichment
  9. 2026-09-30 06:32 UTCGHSA enrichment
  10. 2026-09-30 02:49 UTCGHSA enrichment
  11. 2026-09-29 23:07 UTCGHSA enrichment
  12. 2026-09-29 19:24 UTCGHSA enrichment
  13. 2026-09-29 15:41 UTCEG score recompute
  14. 2026-09-29 15:41 UTCGHSA enrichment
  15. 2026-09-29 11:58 UTCGHSA enrichment
  16. 2026-09-29 08:13 UTCGHSA enrichment
  17. 2026-09-29 04:31 UTCGHSA enrichment
  18. 2026-09-29 04:00 UTCGHSA enrichment
  19. 2026-09-29 00:35 UTCEG score recompute
  20. 2026-09-29 00:35 UTCGHSA enrichment
  21. 2026-09-28 20:54 UTCEG score recompute
  22. 2026-09-28 20:54 UTCGHSA enrichment
  23. 2026-09-28 17:12 UTCEG score recompute
  24. 2026-09-28 17:12 UTCGHSA enrichment
  25. 2026-09-28 13:52 UTCEPSS rescore
  26. 2026-09-28 13:29 UTCGHSA enrichment
  27. 2026-09-28 12:52 UTCEG score recompute
  28. 2026-09-28 12:52 UTCGHSA enrichment
  29. 2026-09-28 12:31 UTCEG score recompute▲ 0.30
  30. 2026-09-28 12:31 UTCGHSA enrichment
  31. 2026-09-28 12:30 UTCNVD updateCVSS v3 → 9.8
  32. 2026-09-28 12:10 UTCGHSA enrichment
  33. 2026-09-28 09:11 UTCGHSA enrichment
  34. 2026-09-28 08:02 UTCGHSA enrichment
  35. 2026-09-28 04:19 UTCEG score recompute
  36. 2026-09-28 04:19 UTCGHSA enrichment
  37. 2026-09-28 04:02 UTCEG score recompute
  38. 2026-09-28 04:02 UTCGHSA enrichment
  39. 2026-09-28 03:17 UTCGHSA enrichment
  40. 2026-09-27 23:35 UTCEG score recompute
  41. 2026-09-27 23:34 UTCGHSA enrichment
  42. 2026-09-27 23:00 UTCEG score recompute
  43. 2026-09-27 23:00 UTCGHSA enrichment
  44. 2026-09-27 22:20 UTCEG score recompute
  45. 2026-09-27 22:20 UTCGHSA enrichment
  46. 2026-09-27 21:51 UTCCISA KEV update
  47. 2026-09-27 20:22 UTCEG score recompute
  48. 2026-09-27 20:22 UTCGHSA enrichment
  49. 2026-09-27 20:01 UTCEG score recompute
  50. 2026-09-27 20:01 UTCGHSA enrichment
  51. 2026-09-27 19:56 UTCEG score recompute
  52. 2026-09-27 19:56 UTCGHSA enrichment
  53. 2026-09-27 17:24 UTCEG score recompute
  54. 2026-09-27 16:25 UTCEG score recompute
  55. 2026-09-27 16:24 UTCMITRE cvelistV5first tracked

Publicly available exploits

(2 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCThomasPoppelgaard/netscaler-ctx697096-checker
    First seen Sep 28, 2026

    Am I fixed? Was I hacked? Read-only checker for Citrix NetScaler CTX697096 (CVE-2026-88771 – CVE-2026-88778): build, all 8 CVE preconditions, Enhanced ISN, upgrade risks, plus --ioc sweep with every public IoC (webshells, config theft, dropped files, log injection, 17 attacker IPs), each attack tagged before/after your fix.

    Open source ↗
  • GitHub PoCwatchtowrlabs/watchTowr-vs-Citrix-Netscaler-CVE-2026-88771
    First seen Sep 27, 2026
    Open source ↗

Frequently asked(6)

What is CVE-2026-88771?
CVE-2026-88771 is a critical vulnerability published on September 27, 2026. Improper input validation 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 an unauthenticated…
When was CVE-2026-88771 disclosed?
CVE-2026-88771 was first published on September 27, 2026, with the most recent update on September 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-88771 actively exploited?
Yes. CISA added CVE-2026-88771 to the Known Exploited Vulnerabilities catalog on September 27, 2026, affecting Citrix NetScaler. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. A fix is available. Apply it.
What is the CVSS score of CVE-2026-88771?
CVE-2026-88771 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2026-88771?
CVE-2026-88771 affects Citrix NetScaler.
How do I remediate CVE-2026-88771?
A fix for CVE-2026-88771 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-88771 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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