TI-2026-38392 Aliases CVE-2026-53306 GHSA-v222-hvcr-rghc

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

LOW 24CWE-193Published 2026-06-26 · Updated 2026-11-06

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 4 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-193 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00162 5th percentileScored 2026-11-07

Fix Partial Linux (Linux): 5.10.258, 5.15.209, 6.1.175 +5Red Hat: 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Linux	Linux	2.6.29 and later	5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10, 7.1	Patch available	CNA

Linux VendorLinux Affected 2.6.29 and later Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10, 7.1 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:o:linux:linux_kernel::::::::	2.6.29 to before 5.10.258; 5.11 to before 5.15.209; 5.16 to before 6.1.175; 6.2 to before 6.6.141; 6.7 to before 6.12.91; 6.13 to before 6.18.33; 6.19 to before 7.0.10	Vulnerable	Linux

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 2.6.29 to before 5.10.258; 5.11 to before 5.15.209; 5.16 to before 6.1.175; 6.2 to before 6.6.141; 6.7 to before 6.12.91; 6.13 to before 6.18.33; 6.19 to before 7.0.10 Vulnerable ·Linux

Remediation

Fix · CNA Linux (Linux) Fixed in 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10, 7.1

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 7	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 8	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 9	Affected	No fix yet: Fix deferred

Not affected: 1 product

Red Hat Enterprise Linux 6

Timeline

2026-10-02 Threatist record created from CVE-2026-53306
2026-10-03 Alias added: GHSA-v222-hvcr-rghc
2026-11-06 CISA SSVC decision points changed

References

Patch 8

TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3

See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences