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VulnerabilityPublished Updated

CVE-2026-68156: Linux kernel · libceph: refresh auth->authorizer_buf{,_len} after authorizer update

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 9.8 Critical · fixed in 2334e9997308305ee4fd508fdfe6086c4150ed60 : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.6% chance of exploitation in 30 days – higher than 52% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers can reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in 2334e9997308305ee4fd508fdfe6086c4150ed60, 937d61f86d377a3aa578adae7a3dfcecdddf9d89, 79a273df64238a4ade8b709689a78589f755b8ef +7
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 10 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • >=3.4.50 <3.5
  • >=3.9.7 <3.10
Fixed in
  • 2334e9997308305ee4fd508fdfe6086c4150ed60
  • 937d61f86d377a3aa578adae7a3dfcecdddf9d89
  • 79a273df64238a4ade8b709689a78589f755b8ef
  • 75e82e8944ac1efe9fdb88bd2f14d9a031282bdf
  • 0060ec912292a550198d8d18ac95b433c92a7091
  • 26f814187abceee90dbb29a02133adb4786fbb13
  • 9d37aec9ffe4e743dabc3f84502e9723e17a30d4
  • 5ecfcd5c05866f185357700b81b461dae4f5ebb2
  • 3.10
  • 3.5
LinuxLinuxAffected
  • =3.10
Fixed in–

Description

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.

References

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