CVE-2026-43378 in the critical feed json
smb: server: fix use-after-free in smb2_open()
published 2026-05-08 6 mo ago modified 2026-08-05 3 mo ago also EUVD-2026-28684
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 23%
- public exploits
- 0
- none known
Summary
In the Linux kernel, the following vulnerability has been resolved:
smb: server: fix use-after-free in smb2_open()
The opinfo pointer obtained via rcu_dereference(fp->f_opinfo) is dereferenced after rcu_read_unlock(), creating a use-after-free window.
Patch / fix
- Linux Linux 6.1.167, 6.6.130, 6.12.78, 6.18.19, 6.19.9, 7.0
- linux Debian 12 6.1.170-1
- linux Debian 13 6.12.85-1
- linux Debian 14 6.19.10-1
debian advisories DEBIAN-CVE-2026-43378
- linux Ubuntu 22.04 LTS 5.15.0-187.197
- linux Ubuntu 24.04 LTS 6.8.0-134.134
- linux Ubuntu 25.10 6.17.0-40.40
- linux-aws Ubuntu 22.04 LTS 5.15.0-1113.120
- linux-aws Ubuntu 24.04 LTS 6.8.0-1060.63
- linux-aws Ubuntu 25.10 6.17.0-1019.19
- linux-gcp Ubuntu 22.04 LTS 5.15.0-1114.124
- linux-gcp Ubuntu 24.04 LTS 6.8.0-1063.69
ubuntu advisories UBUNTU-CVE-2026-43378
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- git.kernel.org/stable/c/e1b21e6066615e7d3d3a7aa2677e415e563fd7cc commit
- git.kernel.org/stable/c/b720c84087cb547f23ce03eab93568c1769e4556 commit
- git.kernel.org/stable/c/54b48ae83de8bb06e65079d96368efe359d4909c commit
- git.kernel.org/stable/c/8f5b1a7cb009a93c48e9e334a2f59a660f9afc07 commit
- git.kernel.org/stable/c/190e5f808e8058640b408ccfed25440b441a718a commit
- git.kernel.org/stable/c/1e689a56173827669a35da7cb2a3c78ed5c53680 commit
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-43378 updated
kernel: smb: server: fix use-after-free in smb2_open()
-
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernelnot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
- Linux Linux
Classification
- Weakness
-
- CWE-416 Use After Free
- Technology feeds
References
-
git.kernel.org
/stable/c/e1b21e6066615e7d3d3a7aa2677e415e563fd7cc
patch
-
git.kernel.org
/stable/c/b720c84087cb547f23ce03eab93568c1769e4556
patch
-
git.kernel.org
/stable/c/54b48ae83de8bb06e65079d96368efe359d4909c
patch
-
git.kernel.org
/stable/c/8f5b1a7cb009a93c48e9e334a2f59a660f9afc07
patch
-
git.kernel.org
/stable/c/190e5f808e8058640b408ccfed25440b441a718a
patch
-
git.kernel.org
/stable/c/1e689a56173827669a35da7cb2a3c78ed5c53680
patch
Sources
- CVE List CVE-2026-43378
- NVD CVE-2026-43378
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.