CVE-2026-59679

CVE-2026-59679 affects the libXfont2 font-server client (X.Org X11). The function fs_read_glyphs() in src/fc/fserve.c indexes the encoding[] array using num_chars from the FS_QueryXBitmaps16 reply, but that array was allocated based on num_extents from the separate FS_QueryXExtents16 reply—two fi...

CVE-2026-59679

fsreadglyphs in the libXfont2 font-server client src/fc/fserve.c indexes the per-character encoding array using numchars from the FSQueryXBitmaps16 reply, but that array was allocated with a size derived from numextents in the separate FSQueryXExtents16 reply. The two CARD32 fields are never...

CVE-2026-44950: Heap-based Buffer Overflow

fsreadglyphs 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 running destination cursor has exceeded the...

CVE-2026-59679: Out-of-bounds Write

fsreadglyphs in the libXfont2 font-server client src/fc/fserve.c indexes the per-character encoding array using numchars from the FSQueryXBitmaps16 reply, but that array was allocated with a size derived from numextents in the separate FSQueryXExtents16 reply. The two CARD32 fields are never...

libxfont2: libXfont2: Privilege Escalation via Heap Buffer Overflow in Font Server Client

A flaw was found in the libXfont2 font-server client. This heap buffer overflow vulnerability allows a malicious font server to send specially crafted glyph data. The fsreadglyphs function fails to properly validate the total size of the incoming data, leading to an overwrite of memory beyond the...

libxfont2: Font Server Client encoding[] Out-Of-Bounds Read/Write

A flaw was found in the libXfont2 font-server client. A remote attacker, by operating a malicious font server, could exploit an out-of-bounds read/write vulnerability. This occurs because the client incorrectly handles font data, leading to an out-of-bounds memory access. This can lead to privile...

Important: Red Hat Security Advisory: libXfont2 security update

An update for libXfont2 is now available for Red Hat Enterprise Linux 7 Extended Lifecycle Support. 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...

libxfont2: Font Server Client encoding[] Out-Of-Bounds Read/Write

A flaw was found in the libXfont2 font-server client. A remote attacker, by operating a malicious font server, could exploit an out-of-bounds read/write vulnerability. This occurs because the client incorrectly handles font data, leading to an out-of-bounds memory access. This can lead to privile...

libxfont2: libXfont2: Privilege Escalation via Heap Buffer Overflow in Font Server Client

A flaw was found in the libXfont2 font-server client. This heap buffer overflow vulnerability allows a malicious font server to send specially crafted glyph data. The fsreadglyphs function fails to properly validate the total size of the incoming data, leading to an overwrite of memory beyond the...

Important: Red Hat Security Advisory: libXfont2 security update

An update for libXfont2 is now available for Red Hat Enterprise Linux 10.0 Extended Update Support. 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...

libxfont2: Font Server Client encoding[] Out-Of-Bounds Read/Write

A flaw was found in the libXfont2 font-server client. A remote attacker, by operating a malicious font server, could exploit an out-of-bounds read/write vulnerability. This occurs because the client incorrectly handles font data, leading to an out-of-bounds memory access. This can lead to privile...

libxfont2: libXfont2: Privilege Escalation via Heap Buffer Overflow in Font Server Client

A flaw was found in the libXfont2 font-server client. This heap buffer overflow vulnerability allows a malicious font server to send specially crafted glyph data. The fsreadglyphs function fails to properly validate the total size of the incoming data, leading to an overwrite of memory beyond the...

Important: Red Hat Security Advisory: libXfont2 security update

An update for libXfont2 is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On. Red Hat Product Security has rated this update as having a security impact of Important. A Common...

RHEL 10 : libXfont2 (RHSA-2026:62123)

The remote Redhat Enterprise Linux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:62123 advisory. X.Org X11 libXfont2 runtime library Security Fixes: libxfont2: Font Server Client encoding Out-Of-Bounds Read/Write CVE-2026-59679...

Alibaba Cloud Linux 3 : 0269: libXfont2 (ALINUX3-SA-2026:0269)

The remote Alibaba Cloud Linux 3 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALINUX3-SA-2026:0269 advisory. Package updates are available for Alibaba Cloud Linux 3 that fix the following vulnerabilities: CVE-2026-44950: A flaw was found in the...

RHEL 8 : libXfont2 (RHSA-2026:61995)

The remote Redhat Enterprise Linux 8 host has a package installed that is affected by multiple vulnerabilities as referenced in the RHSA-2026:61995 advisory. X.Org X11 libXfont2 runtime library Security Fixes: libxfont2: Font Server Client encoding Out-Of-Bounds Read/Write CVE-2026-59679...

RHEL 7 : libXfont2 (RHSA-2026:62231)

The remote Redhat Enterprise Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:62231 advisory. X.Org X11 libXfont2 runtime library Security Fixes: libxfont2: Font Server Client encoding Out-Of-Bounds Read/Write CVE-2026-59679...

libxfont2: libXfont2: Privilege Escalation via Heap Buffer Overflow in Font Server Client

A flaw was found in the libXfont2 font-server client. This heap buffer overflow vulnerability allows a malicious font server to send specially crafted glyph data. The fsreadglyphs function fails to properly validate the total size of the incoming data, leading to an overwrite of memory beyond the...

libxfont2: Font Server Client encoding[] Out-Of-Bounds Read/Write

A flaw was found in the libXfont2 font-server client. A remote attacker, by operating a malicious font server, could exploit an out-of-bounds read/write vulnerability. This occurs because the client incorrectly handles font data, leading to an out-of-bounds memory access. This can lead to privile...

Important: Red Hat Security Advisory: libXfont2 security update

An update for libXfont2 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...