CVE-2026-8451: Insufficient input validation leading to memory overread
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
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
Description quoted from the CVE record (assigned by NetScaler, published 2026-06-30).
Weakness: CWE-125 Out-of-bounds Read
How it can be exploited
Exploitable over the network with low attack complexity with no special attack requirements needing no privileges and no user interaction. Impact: confidentiality high, integrity low, availability 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
CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: yes. Technical impact: total.
Public exploit evidence (Exploit Observer)
Also known as: BDU:2026-08971, EUVD-2026-40305, GHSA-6659-v5cc-894x
VEDAS cluster: VEDAS:GAZEBOGOLEM
Exploit Observer links 4 pieces of public exploit code or detection modules that name this CVE or one of its aliases.
Exploit code and modules (4)
Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.
- Code repository: https://github.com/0xblackash/cve-2026-8451
- Code repository: https://github.com/amnsecurity/cve-2026-8451-citrixbleed
- Code repository: https://github.com/attarwahyup/netscaler-cve-2026-8451
- Code repository: https://github.com/watchtowrlabs/watchtowr-vs-netscaler-cve-2026-8451
Research and write-ups (1)
- Research or write-up: https://labs.watchtowr.com/citrixbleed-to-infinity-and-beyond-citrix-netscaler-pre-auth-memory-overread-cve-2026-8451
Vulnerability databases and vendor advisories (4)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-40305
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-6659-v5cc-894x
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-8451
- Vulnerability database or vendor advisory: https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX696604&articleTitle=CTX696604_NetScaler_ADC_and_NetScaler_Gateway_Security_Bulletin_for_CVE_2026_8451_CVE_2026_8452_CVE_2026_8655_CVE_2026_10816_CVE_2026_10817_and_CVE_2026_13474
5 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.005
low predicted chance of attack - VEDAS
- 0.976
strong exploit evidence - On CISA KEV
- Not listed
- Detection rule
- None yet
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| NetScaler ADC | from 14.1 before 72.61 from 13.1 before 63.18 from 14.1 FIPs before 72.61 from 13.1 FIPS and NDcPP before 37.272 | Not stated |
| NetScaler Gateway | from 14.1 before 72.61 from 13.1 before 63.18 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
Exploit Observer also maps it to: citrix netscaler_application_delivery_controller, citrix netscaler_gateway, citrix_systems_inc. netscaler_adc, citrix_systems_inc. netscaler_adc_fips, citrix_systems_inc. netscaler_gateway.
How to fix it
Fixed versions stated in the CVE record: 72.61, 63.18, 37.272.
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
Advisories on this CVE
- Citrix NetScaler “CitrixBleed 3” (CVE-2026-3055 / -4368) and CVE-2026-8451, Mar and Jun 2026 (30 Jun 2026)
References
Other references
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.