Off-by-one in Linux kernel - CVE-2026-53263

 

Off-by-one in Linux kernel - CVE-2026-53263

Published: June 26, 2026


Vulnerability identifier: #VU135485
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-53263
CWE-ID: CWE-193
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to an off-by-one error in lowpan_iphc_mcast_ctx_addr_compress() when compressing multicast context addresses. A remote attacker can send network traffic that triggers the vulnerable compression path to disclose sensitive information.

Uninitialized kernel stack memory may be transmitted over the network via lowpan_push_hc_data().


Affected software

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

How to mitigate CVE-2026-53263

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13

External References

Related Security Bulletins