CVE-2026-68156

Critical

In the Linux kernel, the following vulnerability has been resolved: libceph: refresh auth->authorizer_buf{,_len} after authorizer update ceph_x_create_authorizer() caches au->buf->vec.iov_base and au->buf->vec.iov_len in struct ceph_auth_handshake. These cached values are then used by the messenger connect code when sending the authorizer. ceph_x_update_authorizer() can rebuild the authorizer when a newer service ticket is available. If the rebuilt authorizer no longer fits in the existing buffer, ceph_x_build_authorizer() drops its reference to au->buf and allocates a new one. If this is the final reference, ceph_buffer_put() frees the old ceph_buffer and its vec.iov_base, but auth->authorizer_buf still points at that freed memory. A subsequent msgr1 reconnect can therefore queue the stale pointer and trigger a KASAN slab-use-after-free in _copy_from_iter() while tcp_sendmsg() copies the authorizer. Refresh auth->authorizer_buf and auth->authorizer_buf_len after a successful authorizer rebuild so the messenger sends the current buffer.

Package Linux Kernel
Published 2026-08-10
Last modified 2026-08-19
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

9.8

out of 10
Critical
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected versions

Linux kernel versions 3.4.50, 3.9.7, 3.10 and later are affected. Fixed in 5.10.265, 5.15.216, 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2 and their respective stable series.

Affected from
≥ 3.4.50 ≥ 3.9.7 ≥ 3.10
Fixed in
✓ 5.10.265 5.10.x ✓ 5.15.216 5.15.x ✓ 6.1.183 6.1.x ✓ 6.6.148 6.6.x ✓ 6.12.101 6.12.x ✓ 6.18.42 6.18.x ✓ 7.1.6 7.1.x ✓ 7.2

References

8 total
Showing 5 of 8 references View all on NVD

Frequently asked questions

  • What is CVE-2026-68156?

    CVE-2026-68156 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10 . It affects Linux kernel versions from 3.4.50 onward and has been patched in 5.10.265, 5.15.216, 6.1.183 and others. CVE-2026-68156 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-68156?

    CVE-2026-68156 has a CVSS score of 9.8 out of 10, rated Critical severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-68156?

    Yes. CVE-2026-68156 has been patched. Fixed versions include 5.10.265, 5.15.216, 6.1.183 and others. If you are running Linux kernel 3.4.50 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-68156 actively exploited?

    No. CVE-2026-68156 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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