CVE-2026-23456

HIGHCVSS 8.2/10EPSS 0.44%

Last modified

CVE-2026-23456 is a high-severity vulnerability rated 8.2/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case In decode_int(), the CONS case calls get_bits(bs, 2) to read a length value, then calls get_uint(bs, len) without checking that len bytes remain in the buffer. The existing boundary check only validates the 2 bits for get_bits(), not the subsequent 1-4 bytes that get_uint() reads. EPSS estimates a 0.44% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case In decode_int(), the CONS case calls get_bits(bs, 2) to read a length value, then calls get_uint(bs, len) without checking that len bytes remain in the buffer. The existing boundary check only validates the 2 bits for get_bits(), not the subsequent 1-4 bytes that get_uint() reads. This allows a malformed H.323/RAS packet to cause a 1-4 byte slab-out-of-bounds read. Add a boundary check for len bytes after get_bits() and before get_uint().

Metrics

CVSS 3.1
8.2/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

EPSS Probability
0.44%

35.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 2.6.17, < 5.10.253
LinuxLinux Kernel>= 5.11, < 5.15.203
LinuxLinux Kernel>= 5.16, < 6.1.167
LinuxLinux Kernel>= 6.2, < 6.6.130
LinuxLinux Kernel>= 6.7, < 6.12.78
LinuxLinux Kernel>= 6.13, < 6.18.20
LinuxLinux Kernel>= 6.19, < 6.19.10
LinuxLinux Kernel7.0Rc1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-23456?
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case In decode_int(), the CONS case calls get_bits(bs, 2) to read a length value, then calls get_uint(bs, len) without checking that len bytes remain in the buffer. The existing boundary check only validates the 2 bits for get_bits(), not the subsequent 1-4 bytes that get_uint() reads. This allows a malformed H.323/RAS packet to cause a 1-4 byte slab-out-of-bounds read. Add a boundary check for len bytes after get_bits() and before get_uint().
How severe is CVE-2026-23456?
CVE-2026-23456 has a CVSS score of 8.2/10 (HIGH severity). The EPSS model estimates a 0.44% probability of exploitation in the next 30 days.
How do I fix CVE-2026-23456?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-23456?

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Source: NVD / NIST