CVE-2026-46181 | RDMA/mlx4: Fix mis-use of RCU in mlx4_srq_event()

In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx4: Fix mis-use of RCU in mlx4_srq_event() Sashiko points out the radix_tree itself is RCU safe, but nothing ever frees the mlx4_srq struct with RCU, and it isn't even accessed within the RCU critical section. It also will crash if an event is delivered before the srq object is finished initializing. Use the spinlock since it isn't easy to make RCU work, use refcount_inc_not_zero() to protect against partially initialized objects, and order the refcount_set() to be after the srq is fully initialized.

Published: 2026-05-28 Last update: 2026-07-02 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-46181 is rated Low Risk (32.5/100): CVSS High severity, with low exploitation likelihood (EPSS 0.14%). 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-2026-46181

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 2026-06-15 0.02% 0.14% +0.12%
2 2026-05-28 — 0.02% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-46181

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
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.
 1.8 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67
7.0 3.1 HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
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.
 1.0 5.9 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Weakness enumeration for CVE-2026-46181

GitHub Security Advisory for CVE-2026-46181

GHSA-pw2f-xmgc-f22m · Severity: high — In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx4: Fix mis-use of...

OS Trackers for CVE-2026-46181

vendor priority summary link
debian not yet assigned CVE-2026-46181 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-46181
redhat high — https://access.redhat.com/security/cve/CVE-2026-46181
suse — — https://www.suse.com/security/cve/CVE-2026-46181/
ubuntu medium CVE-2026-46181 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1422 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1024, ignored 170, needed 137, released 84, not-affected 7. https://ubuntu.com/security/CVE-2026-46181

Affected software / configurations for CVE-2026-46181

Vendor Product Version Raw CPE
linux linux_kernel >= 4.9, < 6.18.30 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.19, < 7.0.7 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 7.1 cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
linux linux_kernel 7.1 cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*

References for CVE-2026-46181

cvelogic Threat Intelligence