In the Linux kernel, the following vulnerability has been resolved: net/mlx5: HWS, change error flow on matcher disconnect Currently, when firmware failure occurs during matcher disconnect flow, the error flow of the function reconnects the matcher back and returns an error, which continues running the calling function and eventually frees the matcher that is being disconnected. This leads to a case where we have a freed matcher on the matchers list, which in turn leads to use-after-free and eventual crash. This patch fixes that by not trying to reconnect the matcher back when some FW command fails during disconnect. Note that we're dealing here with FW error. We can't overcome this problem. This might lead to bad steering state (e.g. wrong connection between matchers), and will also lead to resource leakage, as it is the case with any other error handling during resource destruction. However, the goal here is to allow the driver to continue and not crash the machine with use-after-free error.
Conclusion & alert: CVE-2025-21751 is rated Low Risk (35.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.21%). Mandatory action: 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.
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% | 0.21% | +0.19% |
| 2 | 2026-05-08 | 0.07% | 0.02% | -0.05% |
| 3 | 2026-04-07 | — | 0.07% | — |
Full EPSS history (4 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.8 | 3.1 | HIGH |
|
1.8 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2025-21751 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2025-21751 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-21751 |
suse
|
medium | CVE-2025-21751 severity moderate: SUSE including 64 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 283 product×package rows across 50 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Availability Extension 12 SP5, … (50 product lines)): Known Not Affected 245, Fixed 38. | https://www.suse.com/security/cve/CVE-2025-21751/ |
ubuntu
|
medium | CVE-2025-21751 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, ignored 169, needed 108, released 92, not-affected 37. | https://ubuntu.com/security/CVE-2025-21751 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| linux | linux_kernel | < 6.13.3 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |