What is CVE-2026-98171?

CVE-2026-98171 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10, affecting Linux kernel versions from 4.19 onward and patched in 6.1.189, 6.6.158, 6.12.112 and others. CVE-2026-98171 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-98171?

CVE-2026-98171 has a CVSS score of 8.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-98171?

Yes, CVE-2026-98171 has been patched. Fixed versions include 6.1.189, 6.6.158, 6.12.112 and others. If you are running Linux kernel 4.19 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-98171 actively exploited?

CVE-2026-98171 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-98171

High

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs Fix several related bounds checking and pointer lifecycle issues in receive_encrypted_standard()'s handling of compound encrypted frames: - Clear next_buffer after assigning it to server->bigbuf. A stale next_buffer pointer can lead to a use-after-free on subsequent error paths. - Update pdu_length to the decrypted plaintext size (buf_size). Using the pre-decryption length allows NextCommand to point into stale ciphertext residue. - Reject next_cmd values smaller than MID_HEADER_SIZE(server). - Fix an integer overflow in the upper bound check by verifying pdu_length - next_cmd < MID_HEADER_SIZE(server), ensuring the trailing slice is large enough for a header.

Package Linux Kernel

Published 2026-10-06

Last modified 2026-10-07

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

8.8

out of 10

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Affected versions

Linux kernel versions 4.19 and later are affected. Fixed in 6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8, 7.3-rc4 and their respective stable series.

Affected from

≥ 4.19

Fixed in

✓ 6.1.189 6.1.x ✓ 6.6.158 6.6.x ✓ 6.12.112 6.12.x ✓ 6.18.54 6.18.x ✓ 7.2.8 7.2.x ✓ 7.3-rc4

References

6 total

Showing 5 of 6 references View all on NVD

Details

CVE ID CVE-2026-98171

Severity High

CVSS score 8.8 / 10

CVSS version 3.1

Published 2026-10-06

Modified 2026-10-07

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-98171?

CVE-2026-98171 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10 . It affects Linux kernel versions from 4.19 onward and has been patched in 6.1.189, 6.6.158, 6.12.112 and others. CVE-2026-98171 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-98171?

CVE-2026-98171 has a CVSS score of 8.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-98171?

Yes. CVE-2026-98171 has been patched. Fixed versions include 6.1.189, 6.6.158, 6.12.112 and others. If you are running Linux kernel 4.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-98171 actively exploited?

No. CVE-2026-98171 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.