Bug 2538967 (CVE-2026-93990) - CVE-2026-93990 expat: Expat: XML Injection via Malformed UTF-16 Input
Summary: CVE-2026-93990 expat: Expat: XML Injection via Malformed UTF-16 Input
Keywords:
Status: NEW
Alias: CVE-2026-93990
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2540016 2540017
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-22 21:51 UTC by OSIDB Bzimport
Modified: 2026-10-01 12:00 UTC (History)
20 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2026:72619 0 None None None 2026-09-28 15:23:07 UTC
Red Hat Product Errata RHBA-2026:72622 0 None None None 2026-09-28 15:34:10 UTC
Red Hat Product Errata RHBA-2026:74151 0 None None None 2026-09-30 22:20:43 UTC
Red Hat Product Errata RHBA-2026:74467 0 None None None 2026-10-01 12:00:08 UTC
Red Hat Product Errata RHSA-2026:72448 0 None None None 2026-09-28 11:13:27 UTC
Red Hat Product Errata RHSA-2026:72663 0 None None None 2026-09-28 20:47:34 UTC
Red Hat Product Errata RHSA-2026:74001 0 None None None 2026-09-30 16:31:28 UTC

Description OSIDB Bzimport 2026-09-22 21:51:36 UTC 
Expat through 2.8.4 fails to validate low surrogates following high surrogates in UTF-16 input, allowing malformed UTF-16 sequences to be accepted. Attackers can craft UTF-16 encoded XML with lone high surrogates that consume following code units, hiding markup characters from the parser and enabling XML injection attacks.
Comment 2 Jon Orris 2026-09-28 11:13:25 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:72448 https://access.redhat.com/errata/RHSA-2026:72448
Comment 3 Jon Orris 2026-09-28 11:13:26 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:72448 https://access.redhat.com/errata/RHSA-2026:72448
Comment 4 Jon Orris 2026-09-28 20:47:32 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:72663 https://access.redhat.com/errata/RHSA-2026:72663
Comment 5 Jon Orris 2026-09-30 16:31:25 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:74001 https://access.redhat.com/errata/RHSA-2026:74001
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