DaystoPatch

CitrixExploited incident

NetScaler ADC and Gateway authentication bypass via alternate path (SAML/AAA)

CVE-2026-19490, CVE-2026-19489Critical, CVSS 9.3In CISA's Known Exploited Vulnerabilities catalog since 9 Sep 2026

  • Exploited after a fix existed
FixedFixed for every supported version on the day it became public.

Response

Silence
0h
First public report to first vendor statement
Exposure
same day
First public report to first fix
Follow-through
same day
First public report to a fix for every supported version
  • Vendor silent
  • Vendor statement, no fix
  • Fixed for some versions
  • Fixed when disclosed
  • Date only, no time of day

Timeline and evidence

Open a moment to see its source and archived quote.

  1. First public report

    CVE record CVE-2026-19490 (CNA: NetScaler)CuratedQuote verified

    "datePublished":"2026-08-19T12:54:39.730Z"

    Coordinated disclosure: Citrix's bulletin with fixes was the first public signal. Exploitation began around 2026-09-03, one day after a public exploit appeared (Previdian via SecurityWeek).

    Recorded time
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    Curated. Found by a researcher, with a verbatim quote and link.
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    sha256:9588056d3bbcf625…
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    6 more sources for this moment
    Citrix advisory CTX696939ClaimedQuote verified19 Aug 2026

    NetScaler ADC and NetScaler Gateway Security Bulletin for CVE-2026-19489 and CVE-2026-19490

    The vendor's own disclosure.

    Source
    Citrix advisory CTX696939 vendor advisory
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    sha256:1ad2ea838d141d0e…
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    CVE.org record CVE-2026-19490ClaimedQuote verified19 Aug 2026, 12:54 UTC

    Vulnerability in NetScaler ADC and NetScaler Gateway.

    CVE record published.

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    Bluesky postClaimedQuote not checked yet19 Aug 2026, 13:38 UTC

    NetScaler ADC and NetScaler Gateway Security Bulletin for CVE-2026-19489 and CVE-2026-19490

    Earliest third-party post we hold.

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    Bluesky post social
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    Mastodon postClaimedQuote not checked yet19 Aug 2026, 15:23 UTC

    CVE-2026-19490 (CVSS 9.3) is a critical NetScaler authentication bypass in NetScaler Gateway and ADC. Patch now to block unauthenticated access. # NetScaler # Citrix # CVE202619490

    Earliest third-party post we hold.

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    Mastodon post social
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    CISA KEV (CVE-2026-19490)ClaimedQuote verified9 Sep 2026

    Citrix NetScaler Authentication Bypass Using an Alternate Path or Channel Vulnerability

    Added to CISA's KEV catalog on 2026-09-09.

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    sha256:ef8fffede5c47200…
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    Hacker NewsClaimedQuote not checked yet14 Sep 2026, 03:45 UTC

    https://bishopfox.com/blog/mind-the-config-detecting-and-weaponizing-netscaler-cve-2026-19490

    Earliest third-party post we hold.

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    Hacker News hn
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  2. Vendor statement

    at disclosure

    CVE record CVE-2026-19490 (CNA: NetScaler)CuratedQuote verified

    "datePublished":"2026-08-19T12:54:39.730Z"

    Recorded time
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    To the minute
    Origin
    Curated. Found by a researcher, with a verbatim quote and link.
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    Found in the archived copy
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    sha256:9588056d3bbcf625…
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    1 more source for this moment
    Citrix bulletin CTX696939CuratedQuote not checked yet19 Aug 2026

    2026-08-19 Initial publication

    Only one changelog entry; the bulletin does not say the flaw is exploited.

    Source
    Citrix bulletin CTX696939 vendor advisory
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    Curated. Found by a researcher, with a verbatim quote and link.
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    Not checked yet
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  3. First workaround

    No official mitigation found yet.

  4. First fix

    date onlysame day

    Citrix bulletin CTX696939CuratedQuote verified

    NetScaler ADC and NetScaler Gateway 14.1-73.32 and later releases

    Fixed builds listed in the bulletin, whose only changelog entry is the 2026-08-19 initial publication.

    Source
    Citrix bulletin CTX696939 vendor advisory
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    Origin
    Curated. Found by a researcher, with a verbatim quote and link.
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    Found in the archived copy
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    sha256:1ad2ea838d141d0e…
    Used in metrics
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    Dispute this timestamp

  5. Fixed for all versions

    date onlysame day

    Citrix bulletin CTX696939CuratedQuote verified

    NetScaler ADC 13.1-FIPS and 13.1-NDcPP 13.1-37.277 and later releases of 13.1-FIPS and 13.1-NDcPP

    All four supported branches (14.1, 13.1, 14.1-FIPS, 13.1-FIPS/NDcPP) had fixes in the initial bulletin.

    Source
    Citrix bulletin CTX696939 vendor advisory
    Recorded time
    Precision
    Date only (no time of day is shown)
    Origin
    Curated. Found by a researcher, with a verbatim quote and link.
    Quote check
    Found in the archived copy
    Snapshot
    sha256:1ad2ea838d141d0e…
    Used in metrics
    Yes
    Dispute this timestamp

Send this to your boss

No brief for this incident yet. We write one for every open incident and every critical bug exploited before a fix.

Affected products

  • NetScaler ADC
  • NetScaler Gateway
  • NetScaler ADC FIPS and NDcPP
How we built this timeline

Bulletin CTX696939 also fixes CVE-2026-19489 (SIP ALG memory overflow, not in KEV). Exploitation came after the fix: SecurityWeek (10 Sep 2026) reports exploitation 'since at least September 3, one day after an exploit targeting it was published on GitHub' per Previdian;

KEV added 9 Sep 2026. Previdian said the evidence did not confirm successful compromise.

Exposure requires a Gateway or AAA virtual server; on newer builds only when a SAML action is configured. The live bulletin (fetched 22 Oct 2026) still has a single changelog entry and does not mention exploitation; no Wayback check was possible because the Wayback Machine was offline during research.

Related

Citrix report card