CVE-2026-43239 | smb: client: prevent races in ->query_interfaces()

In the Linux kernel, the following vulnerability has been resolved: smb: client: prevent races in ->query_interfaces() It was possible for two query interface works to be concurrently trying to update the interfaces. Prevent this by checking and updating iface_last_update under iface_lock.

Published: 2026-05-06 Last update: 2026-05-12 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-43239 is rated Low Risk (36.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-43239

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-07 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-43239

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Weakness enumeration for CVE-2026-43239

GitHub Security Advisory for CVE-2026-43239

GHSA-5w3w-mcf7-v883 · Severity: high — In the Linux kernel, the following vulnerability has been resolved: smb: client: prevent races...

OS Trackers for CVE-2026-43239

vendor priority summary link
debian unimportant CVE-2026-43239 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2026-43239
redhat medium — https://access.redhat.com/security/cve/CVE-2026-43239
suse medium — https://www.suse.com/security/cve/CVE-2026-43239/
ubuntu medium CVE-2026-43239 medium priority: Ubuntu including 161 source packages (linux, linux-allwinner-5.19, …), 1449 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1048, ignored 173, needed 129, released 83, not-affected 10, needs-triage 5, pending 1. https://ubuntu.com/security/CVE-2026-43239

Affected software / configurations for CVE-2026-43239

Vendor Product Version Raw CPE
linux linux_kernel >= 5.19.1, < 6.6.128 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.75 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.18.16 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.19, < 6.19.6 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 5.19 cpe:2.3:o:linux:linux_kernel:5.19:-:*:*:*:*:*:*
linux linux_kernel 5.19 cpe:2.3:o:linux:linux_kernel:5.19:rc4:*:*:*:*:*:*
linux linux_kernel 5.19 cpe:2.3:o:linux:linux_kernel:5.19:rc5:*:*:*:*:*:*
linux linux_kernel 5.19 cpe:2.3:o:linux:linux_kernel:5.19:rc6:*:*:*:*:*:*
linux linux_kernel 5.19 cpe:2.3:o:linux:linux_kernel:5.19:rc7:*:*:*:*:*:*
linux linux_kernel 5.19 cpe:2.3:o:linux:linux_kernel:5.19:rc8:*:*:*:*:*:*

References for CVE-2026-43239

cvelogic Threat Intelligence