Critical RHSA-2026:59312 2 CVEs

Red Hat Security Advisory: libXfont2 security update

Published Aug 25, 2026 · Updated Oct 7, 2026

Ecosystem: Red Hat

Fixed packages 3

Release	Package	Fixed in
Red Hat · RHEL 9.4 E4S rhel_e4s:9.4::appstream	libXfont2	0:2.0.3-12.el9_4.3
Red Hat · RHEL 9.4 E4S rhel_e4s:9.4::appstream	libXfont2-debuginfo	0:2.0.3-12.el9_4.3
Red Hat · RHEL 9.4 E4S rhel_e4s:9.4::appstream	libXfont2-debugsource	0:2.0.3-12.el9_4.3

Vulnerabilities 2

Critical 9.0

CVE-2026-44950

fs_read_glyphs() heap buffer overflow via cumulative glyph data overflow in libXfont2

fs_read_glyphs() in the libXfont2 font-server client (src/fc/fserve.c) copies each glyph's bitmap into a single buffer. Existing checks validates only that the source slice (position, length) lies within the source bitmap buffer. It does not check whether the…

SUSE Image SLES15-SP6-SAP-Hardened-BYOS Image SLES15-SP7-SAP-GCE Image SLES-SAP-GCE-3P Debian Ubuntu Azure Linux

Sep 10, 2026
Critical 9.0

CVE-2026-59679

fs_read_glyphs() heap OOB read/write via encoding array index mismatch in libXfont2

fs_read_glyphs() in the libXfont2 font-server client (src/fc/fserve.c) indexes the per-character encoding[] array using num_chars from the FS_QueryXBitmaps16 reply, but that array was allocated with a size derived from num_extents in the separate FS_QueryXExt…

SUSE Image SLES15-SP6-SAP-Azure-3P Image SLES15-SP6-SAPCAL-Azure Image SLES15-SP7-SAPCAL-Azure Debian Ubuntu Azure Linux

Sep 10, 2026

References

article
https://access.redhat.com/security/updates/classification/#important
report
https://bugzilla.redhat.com/show_bug.cgi?id=2509620
report
https://bugzilla.redhat.com/show_bug.cgi?id=2509622
advisory
https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_59312.json
report
https://access.redhat.com/security/cve/CVE-2026-44950
advisory
https://www.cve.org/CVERecord?id=CVE-2026-44950
advisory
https://nvd.nist.gov/vuln/detail/CVE-2026-44950
report
https://access.redhat.com/security/cve/CVE-2026-59679
advisory
https://www.cve.org/CVERecord?id=CVE-2026-59679
advisory
https://nvd.nist.gov/vuln/detail/CVE-2026-59679