{"schema_version": "1.7.0", "id": "RLSA-2026:28923", "modified": "2026-06-25T06:04:16.826435Z", "published": "2026-06-25T06:00:31.266414Z", "upstream": ["CVE-2026-50256", "CVE-2026-50257", "CVE-2026-50258", "CVE-2026-50259", "CVE-2026-50260", "CVE-2026-50261", "CVE-2026-50262", "CVE-2026-50263", "CVE-2026-50264"], "summary": "Important: tigervnc security update", "details": "Virtual Network Computing (VNC) is a remote display system which allows users to view a computing desktop environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures. TigerVNC is a suite of VNC servers and clients.\n\nSecurity Fix(es):\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libXfont2 name length mismatch (CVE-2026-50256)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in miSyncDestroyFence() (CVE-2026-50257)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in XKB key types due to unchecked shift levels (CVE-2026-50258)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in XKB SetMap request via mapWidths indexing (CVE-2026-50259)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in FreeCounter() (CVE-2026-50260)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in SyncChangeCounter() (CVE-2026-50261)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds read/write in GLX ChangeDrawableAttributes (CVE-2026-50262)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free information disclosure in CreateSaverWindow() (CVE-2026-50263)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds heap write in DRI2 DRIGetBuffers/DRIGetBuffersWithFormat (CVE-2026-50264)\n\nFor 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.", "severity": [{"type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}], "affected": [{"package": {"ecosystem": "Rocky Linux:8", "name": "tigervnc", "purl": "pkg:rpm/rocky-linux/tigervnc?distro=rocky-linux-8&epoch=0"}, "ranges": [{"type": "ECOSYSTEM", "events": [{"introduced": "0"}, {"fixed": "0:1.15.0-10.el8_10"}], "database_specific": {"yum_repository": "AppStream"}}]}], "references": [{"type": "ADVISORY", "url": "https://errata.rockylinux.org/RLSA-2026:28923"}, {"type": "REPORT", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2485380"}, {"type": "REPORT", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2485382"}, {"type": "REPORT", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2485383"}, {"type": "REPORT", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2485384"}, {"type": "REPORT", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2485385"}, {"type": "REPORT", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2485386"}, {"type": "REPORT", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2485387"}, {"type": "REPORT", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2485388"}, {"type": "REPORT", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2485389"}], "credits": [{"name": "Rocky Enterprise Software Foundation"}, {"name": "Red Hat"}]}