libceph: refresh auth->authorizer_buf{,_len} after authorizer update
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 11 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 3.5, 3.10
- Fix · CNA Linux (Linux) 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
Red Hat 4 advisories
- RHSA-2026:94996 Released 2026-11-04 · Red Hat rating Criticalkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS AUS (v.8.6) bpftool-4.18.0-372.227.1.el8_6, kernel-4.18.0-372.227.1.el8_6, kernel-abi-stablelists-4.18.0-372.227.1.el8_6 +14
- Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) bpftool-4.18.0-372.227.1.el8_6, kernel-4.18.0-372.227.1.el8_6, kernel-abi-stablelists-4.18.0-372.227.1.el8_6 +14
- RHSA-2026:72468 Released 2026-09-28 · Red Hat rating Importantkernel security update
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.169.1.el8_10, kernel-4.18.0-553.169.1.el8_10, kernel-abi-stablelists-4.18.0-553.169.1.el8_10 +19
- Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.169.1.el8_10
- RHSA-2026:72467 Released 2026-09-28 · Red Hat rating Importantkernel-rt security update
- Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.169.1.rt7.510.el8_10, kernel-rt-core-4.18.0-553.169.1.rt7.510.el8_10, kernel-rt-debug-4.18.0-553.169.1.rt7.510.el8_10 +9
- Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.169.1.rt7.510.el8_10, kernel-rt-core-4.18.0-553.169.1.rt7.510.el8_10, kernel-rt-debug-4.18.0-553.169.1.rt7.510.el8_10 +7
Show 1 more Red Hat advisories
- RHSA-2026:70459 Released 2026-09-23 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.50.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.50.1.el9_8, kernel-64k-devel-5.14.0-687.50.1.el9_8 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.50.1.el9_8, kernel-64k-5.14.0-687.50.1.el9_8, kernel-64k-core-5.14.0-687.50.1.el9_8 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.50.1.el9_8, libperf-5.14.0-687.50.1.el9_8
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.50.1.el9_8, kernel-rt-64k-5.14.0-687.50.1.el9_8, kernel-rt-64k-core-5.14.0-687.50.1.el9_8 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.50.1.el9_8, kernel-rt-core-5.14.0-687.50.1.el9_8, kernel-rt-debug-5.14.0-687.50.1.el9_8 +9
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:70459 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2026:72468 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:70459 |
| Red Hat Enterprise Linux BaseOS AUS (v.8.6) | Fixed | RHSA-2026:94996 |
| Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) | Fixed | RHSA-2026:94996 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2026:72468 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:70459 |
| Red Hat Enterprise Linux NFV (v. 8) | Fixed | RHSA-2026:72467 |
| Red Hat Enterprise Linux RT (v. 8) | Fixed | RHSA-2026:72467 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2026:70459 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:70459 |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2026-68156
- 2026-10-03 Alias added: GHSA-rf74-56p2-8jqj
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-20 Weakness changed · CISA ADP
- 2026-11-04 Fix available: RHSA-2026:94996 · Red Hat
- 2026-11-04 Fix available: Red Hat Enterprise Linux BaseOS AUS (v.8.6), Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/2334e9997308305ee4fd508fdfe6086c4150ed60
- https://git.kernel.org/stable/c/79a273df64238a4ade8b709689a78589f755b8ef
- https://git.kernel.org/stable/c/26f814187abceee90dbb29a02133adb4786fbb13
- https://git.kernel.org/stable/c/9d37aec9ffe4e743dabc3f84502e9723e17a30d4
- https://git.kernel.org/stable/c/75e82e8944ac1efe9fdb88bd2f14d9a031282bdf
- https://git.kernel.org/stable/c/0060ec912292a550198d8d18ac95b433c92a7091
- https://git.kernel.org/stable/c/5ecfcd5c05866f185357700b81b461dae4f5ebb2
- https://git.kernel.org/stable/c/937d61f86d377a3aa578adae7a3dfcecdddf9d89
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Sources
- CVE-2026-68156 · CVE Program
- CVE-2026-68156 · NVD
- FIRST EPSS
- GHSA-rf74-56p2-8jqj · GitHub Advisory Database · CC BY 4.0
- CVE-2026-68156 · Red Hat security data · CC BY 4.0
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