Go to homepageCyberStrike

Menu

Star on GitHub · 3.2k
Sign inDownload

CVE-2026-53306

5.5 · MEDIUM

In the Linux kernel, the following vulnerability has been resolved: tty: hvc_iucv: fix off-by-one in number of supported devices MAX_HVC_IUCV_LINES == HVC_ALLOC_TTY_ADAPTERS == 8.

Published Jun 26, 2026CWE-193EPSS 0.16%

Overview

CVE-2026-53306 is a medium-severity vulnerability. It was published on June 26, 2026 and has a CVSS 3.1 base score of 5.5 (MEDIUM).

This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.

Technical description

In the Linux kernel, the following vulnerability has been resolved:

tty: hvc_iucv: fix off-by-one in number of supported devices

MAX_HVC_IUCV_LINES == HVC_ALLOC_TTY_ADAPTERS == 8.

This is the number of entries in:

static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES];

Sometimes hvc_iucv_table[] is limited by:

(a) if (num > hvc_iucv_devices) // for error detection

or

(b) for (i = 0; i < hvc_iucv_devices; i++) // in 2 places

(so these 2 don't agree; second one appears to be correct to me.)

hvc_iucv_devices can be 0..8. This is a counter.

(c) if (hvc_iucv_devices > MAX_HVC_IUCV_LINES)

If hvc_iucv_devices == 8, (a) allows the code to access hvc_iucv_table[8].

Oops.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

Refgit.kernel.org/stable/c/11207e42a332eb8bbcb9fe74df9edd2a807c5607Refgit.kernel.org/stable/c/3104a3f40feb107f77d7116ad9bf6c210ab7babfRefgit.kernel.org/stable/c/3d3b89e6ab93bdd0efd45828bda6b0e61cc46dffRefgit.kernel.org/stable/c/484357dff256c816d9466bda35eb765685e4dc86Refgit.kernel.org/stable/c/a76511bc654819425d3b15e77b523d7f9d81f064Refgit.kernel.org/stable/c/f1dc8e72de9aabe5d96767a4e97219ac26b79fe5Refgit.kernel.org/stable/c/f2a880e802ad12d1e38039d1334fb1475d0f5241Refgit.kernel.org/stable/c/fed8b8f33a46db0ee2efdb000f4f630c86ed8ca4

How CyberStrike helps

Frequently asked questions

What is CVE-2026-53306?

CVE-2026-53306 is a medium-severity vulnerability. It was published on June 26, 2026 and has a CVSS 3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2026-53306?

This vulnerability has a CVSS 3.1 base score of 5.5, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.

How do I fix or remediate CVE-2026-53306?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2026-53306?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-53306 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related MEDIUM CVEs from 2026

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999