CVE-2026-21529: Microsoft Azure HDInsight · Cross-site Scripting
Affects Microsoft Azure HDInsightSource CVE Database V5
Not known to be exploited · CVSS 5.7 Medium : upgrade to 5.1 when convenient.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 51% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H/E:U/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 10 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Upgrade Microsoft Azure HDInsight to 5.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MicrosoftAzure HDInsight | Affected
| Fixed in
|
AI-suggested
An official fix is available from Microsoft, and because Azure HDInsight is a cloud service, Microsoft manages the remediation on their servers. Users should verify that their Azure HDInsight service is updated according to Microsoft's advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21529. No additional user action is required beyond ensuring the service is current.
Description
Improper neutralization of input during web page generation ('cross-site scripting') in Azure HDInsights allows an authorized attacker to perform spoofing over a network.