[USN-8463-1] LibVNCServer vulnerabilities
[USN-8464-1] LIBNFS vulnerability
[USN-8193-2] libcap vulnerability
[USN-8463-1] LibVNCServer vulnerabilities
==========================================================================
Ubuntu Security Notice USN-8463-1
June 23, 2026
libvncserver vulnerabilities
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 26.04 LTS
- Ubuntu 25.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
Summary:
Several security issues were fixed in LibVNCServer.
Software Description:
- libvncserver: vnc server library
Details:
It was discovered that LibVNCServer had a memory leak in the client cleanup
function. An attacker could possibly use this issue to cause LibVNCServer
to consume memory, leading to a denial of service. This issue only affected
Ubuntu 22.04 LTS. (CVE-2020-29260)
It was discovered that LibVNCServer did not properly validate bounds when
handling UltraZip encoding subrectangles. A remote attacker could possibly
use this issue to obtain sensitive information or cause a denial of
service. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and
Ubuntu 25.04. (CVE-2026-32853)
It was discovered that LibVNCServer did not properly validate return values
in the HTTP proxy handlers. A remote attacker could possibly use this issue
to cause LibVNCServer to crash, resulting in a denial of service. This
issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 25.04.
(CVE-2026-32854)
It was discovered that LibVNCServer did not properly handle Tight encoding
gradient filter rectangles. A remote attacker could use this issue to cause
LibVNCServer to crash, resulting in a denial of service, or possibly
execute arbitrary code. (CVE-2026-44988)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 26.04 LTS
libvncclient1 0.9.15+dfsg-3ubuntu0.1
libvncserver1 0.9.15+dfsg-3ubuntu0.1
Ubuntu 25.10
libvncclient1 0.9.15+dfsg-1ubuntu0.1
libvncserver1 0.9.15+dfsg-1ubuntu0.1
Ubuntu 24.04 LTS
libvncclient1 0.9.14+dfsg-1ubuntu0.1
libvncserver1 0.9.14+dfsg-1ubuntu0.1
Ubuntu 22.04 LTS
libvncclient1 0.9.13+dfsg-3ubuntu0.1
libvncserver1 0.9.13+dfsg-3ubuntu0.1
In general, a standard system update will make all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-8463-1
CVE-2020-29260, CVE-2026-32853, CVE-2026-32854, CVE-2026-44988
Package Information:
https://launchpad.net/ubuntu/+source/libvncserver/0.9.15+dfsg-3ubuntu0.1
https://launchpad.net/ubuntu/+source/libvncserver/0.9.15+dfsg-1ubuntu0.1
https://launchpad.net/ubuntu/+source/libvncserver/0.9.14+dfsg-1ubuntu0.1
https://launchpad.net/ubuntu/+source/libvncserver/0.9.13+dfsg-3ubuntu0.1
[USN-8464-1] LIBNFS vulnerability
==========================================================================
Ubuntu Security Notice USN-8464-1
June 23, 2026
libnfs vulnerability
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 26.04 LTS
- Ubuntu 25.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
Summary:
LIBNFS could be made to crash or run programs if it connected to a
specially crafted NFS server.
Software Description:
- libnfs: NFS client library
Details:
It was discovered that LIBNFS incorrectly handled certain string sizes when
connecting to an NFS server. An attacker could use this issue to cause
LIBNFS to crash, resulting in a denial of service, or possibly execute
arbitrary code.
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 26.04 LTS
libnfs-utils 5.0.2-1ubuntu1.1
libnfs14 5.0.2-1ubuntu1.1
Ubuntu 25.10
libnfs-utils 5.0.2-1ubuntu0.25.10.1
libnfs14 5.0.2-1ubuntu0.25.10.1
Ubuntu 24.04 LTS
libnfs-utils 5.0.2-1ubuntu0.24.04.1
libnfs14 5.0.2-1ubuntu0.24.04.1
Ubuntu 22.04 LTS
libnfs-utils 4.0.0-1ubuntu0.1
libnfs13 4.0.0-1ubuntu0.1
In general, a standard system update will make all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-8464-1
CVE-2026-53689
Package Information:
https://launchpad.net/ubuntu/+source/libnfs/5.0.2-1ubuntu1.1
https://launchpad.net/ubuntu/+source/libnfs/5.0.2-1ubuntu0.25.10.1
https://launchpad.net/ubuntu/+source/libnfs/5.0.2-1ubuntu0.24.04.1
https://launchpad.net/ubuntu/+source/libnfs/4.0.0-1ubuntu0.1
[USN-8193-2] libcap vulnerability
==========================================================================
Ubuntu Security Notice USN-8193-2
June 23, 2026
libcap2 vulnerability
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS
Summary:
libcap could be made to modify capabilities on arbitrary files.
Software Description:
- libcap2: POSIX 1003.1e capabilities library
Details:
USN-8193-1 fixed a vulnerability in libcap. This update provides the
corresponding update for Ubuntu 14.04 LTS, Ubuntu 16.04 LTS,
Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS.
Original advisory details:
Ali Raza discovered that libcap incorrectly handled file capability
updates. A local attacker could possibly use this issue to inject or strip
capabilities into arbitrary executables and escalate privileges.
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 20.04 LTS
libcap-dev 1:2.32-1ubuntu0.2+esm1
Available with Ubuntu Pro
libcap2 1:2.32-1ubuntu0.2+esm1
Available with Ubuntu Pro
libcap2-bin 1:2.32-1ubuntu0.2+esm1
Available with Ubuntu Pro
libpam-cap 1:2.32-1ubuntu0.2+esm1
Available with Ubuntu Pro
Ubuntu 18.04 LTS
libcap-dev 1:2.25-1.2ubuntu0.1~esm2
Available with Ubuntu Pro
libcap2 1:2.25-1.2ubuntu0.1~esm2
Available with Ubuntu Pro
libcap2-bin 1:2.25-1.2ubuntu0.1~esm2
Available with Ubuntu Pro
libpam-cap 1:2.25-1.2ubuntu0.1~esm2
Available with Ubuntu Pro
Ubuntu 16.04 LTS
libcap-dev 1:2.24-12ubuntu0.1~esm2
Available with Ubuntu Pro
libcap2 1:2.24-12ubuntu0.1~esm2
Available with Ubuntu Pro
libcap2-bin 1:2.24-12ubuntu0.1~esm2
Available with Ubuntu Pro
libpam-cap 1:2.24-12ubuntu0.1~esm2
Available with Ubuntu Pro
Ubuntu 14.04 LTS
libcap-dev 1:2.24-0ubuntu2+esm2
Available with Ubuntu Pro
libcap2 1:2.24-0ubuntu2+esm2
Available with Ubuntu Pro
libcap2-bin 1:2.24-0ubuntu2+esm2
Available with Ubuntu Pro
libpam-cap 1:2.24-0ubuntu2+esm2
Available with Ubuntu Pro
In general, a standard system update will make all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-8193-2
https://ubuntu.com/security/notices/USN-8193-1
CVE-2026-4878
