CVE-2023-6549

HIGHNVD 8.29.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2024-01-17), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 8.2 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 4 sources updated this weekExploited in the wild
8.2
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • 716 internet-exposed hosts are running an affected version right now
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 58%CVSS: 8.2Exploit: NoneExposed: 716

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Improper Restriction of Operations within the Bounds of a Memory Buffer in NetScaler ADC and NetScaler Gateway allows Unauthenticated Denial of Service and Out-Of-Bounds Memory Read

Live · internet exposure

716 internet-exposed hosts are running an affected version of CVE-2023-6549 right now.

across 14 countries (Australia, Lithuania, United Kingdom, Bulgaria, Germany)top: netscaler_gateway
See the live KEV-Exposure radar →Found passively from public internet-scan data — aggregate, host-redacted.

EchelonGraph is the only CVE feed that fuses live vulnerability intelligence with its own live internet-exposure radar — so you see not just that a CVE is exploited, but how much of the internet is exposed to it right now.

CVSS v3
8.2
EG Score
9.0(high)
EPSS
99.0%
KEV
⚠ Exploited

Published

January 17, 2024

Last Modified

February 26, 2026

Advisory Details (2)

Auto-updated Jun 3, 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-2023-6549
generic

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https://support.citrix.com/article/CTX584986/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20236548-and-cve20236549

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 59× in last 7d / 225× 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.

Showing the most recent 100 of 406 total refreshes for this CVE.

  1. 2026-07-22 14:07 UTCEPSS rescore
  2. 2026-07-22 14:07 UTCEPSS rescore
  3. 2026-07-22 11:45 UTCGHSA enrichment
  4. 2026-07-22 07:44 UTCGHSA enrichment
  5. 2026-07-22 03:42 UTCGHSA enrichment
  6. 2026-07-21 23:39 UTCGHSA enrichment
  7. 2026-07-21 19:01 UTCEG score recompute
  8. 2026-07-21 19:01 UTCGHSA enrichment
  9. 2026-07-21 15:23 UTCEPSS rescore
  10. 2026-07-21 14:59 UTCGHSA enrichment
  11. 2026-07-21 14:37 UTCCISA KEV update
  12. 2026-07-21 10:57 UTCGHSA enrichment
  13. 2026-07-21 06:55 UTCGHSA enrichment
  14. 2026-07-21 02:53 UTCGHSA enrichment
  15. 2026-07-20 22:51 UTCGHSA enrichment
  16. 2026-07-20 18:49 UTCEG score recompute
  17. 2026-07-20 18:49 UTCGHSA enrichment
  18. 2026-07-20 17:06 UTCEPSS rescore
  19. 2026-07-20 14:48 UTCGHSA enrichment
  20. 2026-07-20 10:40 UTCGHSA enrichment
  21. 2026-07-20 06:39 UTCGHSA enrichment
  22. 2026-07-20 02:06 UTCGHSA enrichment
  23. 2026-07-19 22:05 UTCGHSA enrichment
  24. 2026-07-19 18:04 UTCEG score recompute
  25. 2026-07-19 18:04 UTCGHSA enrichment
Show 75 more
  1. 2026-07-19 14:30 UTCEPSS rescore
  2. 2026-07-19 14:29 UTCEPSS rescore
  3. 2026-07-19 14:02 UTCGHSA enrichment
  4. 2026-07-19 10:01 UTCGHSA enrichment
  5. 2026-07-19 06:00 UTCEG score recompute
  6. 2026-07-19 06:00 UTCGHSA enrichment
  7. 2026-07-19 02:27 UTCEPSS rescore
  8. 2026-07-19 02:27 UTCEPSS rescore
  9. 2026-07-19 01:58 UTCGHSA enrichment
  10. 2026-07-18 21:57 UTCGHSA enrichment
  11. 2026-07-18 17:55 UTCGHSA enrichment
  12. 2026-07-18 13:53 UTCGHSA enrichment
  13. 2026-07-18 09:51 UTCGHSA enrichment
  14. 2026-07-18 05:49 UTCGHSA enrichment
  15. 2026-07-18 01:48 UTCGHSA enrichment
  16. 2026-07-17 21:47 UTCGHSA enrichment
  17. 2026-07-17 17:45 UTCGHSA enrichment
  18. 2026-07-17 13:43 UTCGHSA enrichment
  19. 2026-07-17 09:41 UTCEG score recompute
  20. 2026-07-17 09:41 UTCGHSA enrichment
  21. 2026-07-17 05:40 UTCGHSA enrichment
  22. 2026-07-17 01:38 UTCGHSA enrichment
  23. 2026-07-16 21:37 UTCGHSA enrichment
  24. 2026-07-16 17:35 UTCGHSA enrichment
  25. 2026-07-16 17:04 UTCCISA KEV update
  26. 2026-07-16 17:01 UTCEPSS rescore
  27. 2026-07-16 13:34 UTCGHSA enrichment
  28. 2026-07-16 09:33 UTCGHSA enrichment
  29. 2026-07-16 05:32 UTCGHSA enrichment
  30. 2026-07-16 01:30 UTCGHSA enrichment
  31. 2026-07-15 21:29 UTCGHSA enrichment
  32. 2026-07-15 17:28 UTCGHSA enrichment
  33. 2026-07-15 16:56 UTCEPSS rescore
  34. 2026-07-15 16:49 UTCCISA KEV update
  35. 2026-07-15 15:04 UTCCISA KEV update
  36. 2026-07-15 13:26 UTCGHSA enrichment
  37. 2026-07-15 09:24 UTCGHSA enrichment
  38. 2026-07-15 05:22 UTCGHSA enrichment
  39. 2026-07-15 01:59 UTCEPSS rescore
  40. 2026-07-15 01:59 UTCEPSS rescore
  41. 2026-07-15 01:20 UTCGHSA enrichment
  42. 2026-07-14 21:18 UTCGHSA enrichment
  43. 2026-07-14 18:05 UTCCISA KEV update
  44. 2026-07-14 17:16 UTCGHSA enrichment
  45. 2026-07-14 13:12 UTCGHSA enrichment
  46. 2026-07-14 09:11 UTCGHSA enrichment
  47. 2026-07-14 05:08 UTCGHSA enrichment
  48. 2026-07-14 01:06 UTCGHSA enrichment
  49. 2026-07-13 22:28 UTCEPSS rescore
  50. 2026-07-13 22:28 UTCEPSS rescore
  51. 2026-07-13 21:05 UTCGHSA enrichment
  52. 2026-07-13 17:07 UTCCISA KEV update
  53. 2026-07-13 17:03 UTCGHSA enrichment
  54. 2026-07-13 13:01 UTCGHSA enrichment
  55. 2026-07-13 08:59 UTCGHSA enrichment
  56. 2026-07-13 06:11 UTCEPSS rescore
  57. 2026-07-13 04:57 UTCGHSA enrichment
  58. 2026-07-13 00:56 UTCGHSA enrichment
  59. 2026-07-12 20:54 UTCGHSA enrichment
  60. 2026-07-12 16:50 UTCGHSA enrichment
  61. 2026-07-12 12:48 UTCGHSA enrichment
  62. 2026-07-12 08:46 UTCGHSA enrichment
  63. 2026-07-12 05:45 UTCEPSS rescore
  64. 2026-07-12 05:45 UTCEPSS rescore
  65. 2026-07-12 04:45 UTCGHSA enrichment
  66. 2026-07-12 00:43 UTCGHSA enrichment
  67. 2026-07-11 20:41 UTCGHSA enrichment
  68. 2026-07-11 16:40 UTCGHSA enrichment
  69. 2026-07-11 12:38 UTCGHSA enrichment
  70. 2026-07-11 08:36 UTCGHSA enrichment
  71. 2026-07-11 08:26 UTCEPSS rescore
  72. 2026-07-11 04:35 UTCGHSA enrichment
  73. 2026-07-11 00:34 UTCGHSA enrichment
  74. 2026-07-10 20:32 UTCGHSA enrichment
  75. 2026-07-10 17:52 UTCCISA KEV update

Publicly available exploits

(1 reference)

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

  • Nucleihttp/cves/2023/CVE-2023-6549.yaml
    First seen Jan 1, 2023

    Citrix Netscaler ADC & Gateway - Out-Of-Bounds Memory Read

    Open source ↗

Related CVEs(same CWE)

Frequently asked(6)

What is CVE-2023-6549?
CVE-2023-6549 is a high vulnerability published on January 17, 2024. Improper Restriction of Operations within the Bounds of a Memory Buffer in NetScaler ADC and NetScaler Gateway allows Unauthenticated Denial of Service and Out-Of-Bounds Memory Read
When was CVE-2023-6549 disclosed?
CVE-2023-6549 was first published in the National Vulnerability Database on January 17, 2024, with the most recent update on February 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2023-6549 actively exploited?
Yes. CISA added CVE-2023-6549 to the Known Exploited Vulnerabilities catalog on January 17, 2024, affecting Citrix NetScaler ADC and NetScaler Gateway. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2023-6549?
CVE-2023-6549 has a CVSS v3 base score of 8.2 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2023-6549?
CVE-2023-6549 affects Citrix NetScaler ADC and NetScaler Gateway. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2023-6549?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-6549, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2023-6549

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