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Red Hat Product Errata RHSA-2026:99565 - Security Advisory
Issued:
2026-11-12
Updated:
2026-11-12

RHSA-2026:99565 - Security Advisory

  • Overview
  • Updated Packages

Synopsis

Important: libX11 security update

Type/Severity

Security Advisory: Important

Red Hat Lightspeed patch analysis

Identify and remediate systems affected by this advisory.

View affected systems

Topic

An update for libX11 is now available for Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions and Red Hat Enterprise Linux 8.8 Telecommunications Update Service.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The libX11 packages contain the core X11 protocol client library.

Security Fix(es):

  • libX11: libX11: Heap-based buffer overflow via malicious X server (CVE-2026-88806)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

  • Red Hat Enterprise Linux for x86_64 - Extended Life Cycle Long Life 8.8 x86_64
  • Red Hat Enterprise Linux Server - TUS 8.8 x86_64
  • Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 8.8 ppc64le
  • Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 8.8 x86_64

Fixes

  • BZ - 2538514 - CVE-2026-88806 libX11: libX11: Heap-based buffer overflow via malicious X server

CVEs

  • CVE-2026-88806

References

  • https://access.redhat.com/security/updates/classification/#important
Note: More recent versions of these packages may be available. Click a package name for more details.

Red Hat Enterprise Linux for x86_64 - Extended Life Cycle Long Life 8.8

SRPM
libX11-1.6.8-6.el8_8.1.src.rpm SHA-256: 59e4cfd00cc283b938d7879f886d8e22d953d44f6393ec95f540462ac739718d
x86_64
libX11-1.6.8-6.el8_8.1.i686.rpm SHA-256: 454d0bd865144524b72fa551b9adde7ad59a3823be59212e634be1232ff57aa7
libX11-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: e2b17dea5bcc111ab1260b3d563df6b66eb73884715edd67b437347dbdc913c4
libX11-common-1.6.8-6.el8_8.1.noarch.rpm SHA-256: 41f3d41fcb0d3b42b416285a8e206e4f50bce5b160bd8b6c8c7fda2a9d9f740a
libX11-debuginfo-1.6.8-6.el8_8.1.i686.rpm SHA-256: 322a160b607f6ab6da02f8dec0b36972c08c2a6513865bdc755a5e45112bad97
libX11-debuginfo-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: f04c186fcdb4f98d822aaea4fab48cc11f26139cf7a9224af870cb43864789e5
libX11-debugsource-1.6.8-6.el8_8.1.i686.rpm SHA-256: b07c3f5519615d057da7022898b286497df90534f922ca93a9b28e55b2d70efc
libX11-debugsource-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: 0feddb42a464bf4407cee04b8af2d59441572acbe386a06c02825f4b88e6c105
libX11-devel-1.6.8-6.el8_8.1.i686.rpm SHA-256: b4d96786cba6d403b2d65e92cefb5759b941a55a0402483ff659530e4e850f99
libX11-devel-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: 3c9d0bef53a7c39233bc10bd1656a28e6aebf2aeca9e6853b584b86d44f094d5
libX11-xcb-1.6.8-6.el8_8.1.i686.rpm SHA-256: 7fc4cf3ba87e3aa1fab8363127dd7f40b346125eab9b55e03ce0df407787756c
libX11-xcb-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: d0735233f3212d97cde73987ebc4cc452102e5ffd48e206067de142b9df891c9
libX11-xcb-debuginfo-1.6.8-6.el8_8.1.i686.rpm SHA-256: 22ea23fbda47243ad10fabbef047c582035a14ace2d2f72a6bdc714a87ec588b
libX11-xcb-debuginfo-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: d991458e9a34615434e61f8e0d1ff44edbfc43d773e080f844c909593c8c8bea

Red Hat Enterprise Linux Server - TUS 8.8

SRPM
libX11-1.6.8-6.el8_8.1.src.rpm SHA-256: 59e4cfd00cc283b938d7879f886d8e22d953d44f6393ec95f540462ac739718d
x86_64
libX11-1.6.8-6.el8_8.1.i686.rpm SHA-256: 454d0bd865144524b72fa551b9adde7ad59a3823be59212e634be1232ff57aa7
libX11-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: e2b17dea5bcc111ab1260b3d563df6b66eb73884715edd67b437347dbdc913c4
libX11-common-1.6.8-6.el8_8.1.noarch.rpm SHA-256: 41f3d41fcb0d3b42b416285a8e206e4f50bce5b160bd8b6c8c7fda2a9d9f740a
libX11-debuginfo-1.6.8-6.el8_8.1.i686.rpm SHA-256: 322a160b607f6ab6da02f8dec0b36972c08c2a6513865bdc755a5e45112bad97
libX11-debuginfo-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: f04c186fcdb4f98d822aaea4fab48cc11f26139cf7a9224af870cb43864789e5
libX11-debugsource-1.6.8-6.el8_8.1.i686.rpm SHA-256: b07c3f5519615d057da7022898b286497df90534f922ca93a9b28e55b2d70efc
libX11-debugsource-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: 0feddb42a464bf4407cee04b8af2d59441572acbe386a06c02825f4b88e6c105
libX11-devel-1.6.8-6.el8_8.1.i686.rpm SHA-256: b4d96786cba6d403b2d65e92cefb5759b941a55a0402483ff659530e4e850f99
libX11-devel-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: 3c9d0bef53a7c39233bc10bd1656a28e6aebf2aeca9e6853b584b86d44f094d5
libX11-xcb-1.6.8-6.el8_8.1.i686.rpm SHA-256: 7fc4cf3ba87e3aa1fab8363127dd7f40b346125eab9b55e03ce0df407787756c
libX11-xcb-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: d0735233f3212d97cde73987ebc4cc452102e5ffd48e206067de142b9df891c9
libX11-xcb-debuginfo-1.6.8-6.el8_8.1.i686.rpm SHA-256: 22ea23fbda47243ad10fabbef047c582035a14ace2d2f72a6bdc714a87ec588b
libX11-xcb-debuginfo-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: d991458e9a34615434e61f8e0d1ff44edbfc43d773e080f844c909593c8c8bea

Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 8.8

SRPM
libX11-1.6.8-6.el8_8.1.src.rpm SHA-256: 59e4cfd00cc283b938d7879f886d8e22d953d44f6393ec95f540462ac739718d
ppc64le
libX11-1.6.8-6.el8_8.1.ppc64le.rpm SHA-256: dc18260a9752f197cc6594f9da8cff08ce181c75553488f19ea01bc3784c3d71
libX11-common-1.6.8-6.el8_8.1.noarch.rpm SHA-256: 41f3d41fcb0d3b42b416285a8e206e4f50bce5b160bd8b6c8c7fda2a9d9f740a
libX11-debuginfo-1.6.8-6.el8_8.1.ppc64le.rpm SHA-256: 3465e44976af30c3731570649bc61fb75c9be0043396e2e5ce268bb2030fb915
libX11-debugsource-1.6.8-6.el8_8.1.ppc64le.rpm SHA-256: 07ac7095466d3b8b9d008c611979b67ddb9134c47105fb5cde894b9da0d1bcba
libX11-devel-1.6.8-6.el8_8.1.ppc64le.rpm SHA-256: 3428ecae429e07ffe24d6e3bdc4c259b569c0c89018494729805e806c66647db
libX11-xcb-1.6.8-6.el8_8.1.ppc64le.rpm SHA-256: 3de2c97f01d07736fb44696f37b228c009ca33864b1f0735e91541ca03b3b67a
libX11-xcb-debuginfo-1.6.8-6.el8_8.1.ppc64le.rpm SHA-256: af73ad236628f30575bd4524ccad552018d6e5dbe400422ad6b29e278255f36b

Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 8.8

SRPM
libX11-1.6.8-6.el8_8.1.src.rpm SHA-256: 59e4cfd00cc283b938d7879f886d8e22d953d44f6393ec95f540462ac739718d
x86_64
libX11-1.6.8-6.el8_8.1.i686.rpm SHA-256: 454d0bd865144524b72fa551b9adde7ad59a3823be59212e634be1232ff57aa7
libX11-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: e2b17dea5bcc111ab1260b3d563df6b66eb73884715edd67b437347dbdc913c4
libX11-common-1.6.8-6.el8_8.1.noarch.rpm SHA-256: 41f3d41fcb0d3b42b416285a8e206e4f50bce5b160bd8b6c8c7fda2a9d9f740a
libX11-debuginfo-1.6.8-6.el8_8.1.i686.rpm SHA-256: 322a160b607f6ab6da02f8dec0b36972c08c2a6513865bdc755a5e45112bad97
libX11-debuginfo-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: f04c186fcdb4f98d822aaea4fab48cc11f26139cf7a9224af870cb43864789e5
libX11-debugsource-1.6.8-6.el8_8.1.i686.rpm SHA-256: b07c3f5519615d057da7022898b286497df90534f922ca93a9b28e55b2d70efc
libX11-debugsource-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: 0feddb42a464bf4407cee04b8af2d59441572acbe386a06c02825f4b88e6c105
libX11-devel-1.6.8-6.el8_8.1.i686.rpm SHA-256: b4d96786cba6d403b2d65e92cefb5759b941a55a0402483ff659530e4e850f99
libX11-devel-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: 3c9d0bef53a7c39233bc10bd1656a28e6aebf2aeca9e6853b584b86d44f094d5
libX11-xcb-1.6.8-6.el8_8.1.i686.rpm SHA-256: 7fc4cf3ba87e3aa1fab8363127dd7f40b346125eab9b55e03ce0df407787756c
libX11-xcb-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: d0735233f3212d97cde73987ebc4cc452102e5ffd48e206067de142b9df891c9
libX11-xcb-debuginfo-1.6.8-6.el8_8.1.i686.rpm SHA-256: 22ea23fbda47243ad10fabbef047c582035a14ace2d2f72a6bdc714a87ec588b
libX11-xcb-debuginfo-1.6.8-6.el8_8.1.x86_64.rpm SHA-256: d991458e9a34615434e61f8e0d1ff44edbfc43d773e080f844c909593c8c8bea

The Red Hat security contact is secalert@redhat.com. More contact details at https://access.redhat.com/security/team/contact/.

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