CVE-2025-39947 — net/mlx5e: Harden uplink netdev access against device unbind
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Harden uplink netdev access against device unbind The function mlx5_uplink_netdev_get() gets the uplink netdevice pointer from mdev->mlx5e_res.uplink_netdev. However, the netdevice can be removed and its pointer cleared when unbound from the mlx5_core.eth driver. This results in a NULL pointer, causing a kernel panic. BUG: unable to handle page fault for address: 0000000000001300 at RIP: 0010:mlx5e_vport_rep_load+0x22a/0x270 [mlx5_core] Call Trace: <TASK> mlx5_esw_offloads_rep_load+0x68/0xe0 [mlx5_core] esw_offloads_enable+0x593/0x910 [mlx5_core] mlx5_eswitch_enable_locked+0x341/0x420 [mlx5_core] mlx5_devlink_eswitch_mode_set+0x17e/0x3a0 [mlx5_core] devlink_nl_eswitch_set_doit+0x60/0xd0 genl_family_rcv_msg_doit+0xe0/0x130 genl_rcv_msg+0x183/0x290 netlink_rcv_skb+0x4b/0xf0 genl_rcv+0x24/0x40 netlink_unicast+0x255/0x380 netlink_sendmsg+0x1f3/0x420 __sock_sendmsg+0x38/0x60 __sys_sendto+0x119/0x180 do_syscall_64+0x53/0x1d0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Ensure the pointer is valid before use by checking it for NULL. If it is valid, immediately call netdev_hold() to take a reference, and preventing the netdevice from being freed while it is in use.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.1% (30-day exploitation probability)+1
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ 7a9fb35e8c3a67145fca262c304de65cb2f83abf and < 2cb17c88edd3a1c7aa6bc880dcdb35a6866fcb2e≥ 7a9fb35e8c3a67145fca262c304de65cb2f83abf and < d1f3db4e7a3be29fc17f01850f162363f919370d≥ 7a9fb35e8c3a67145fca262c304de65cb2f83abf and < 8df354eb2dd63d111ed5ae2e956e0dbb22bcf93b≥ 7a9fb35e8c3a67145fca262c304de65cb2f83abf and < 6b4be64fd9fec16418f365c2d8e47a7566e9eba5version 5.13 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
≥ 5.13 and < 6.6.108≥ 6.7 and < 6.12.49≥ 6.13 and < 6.16.9version 6.17-rc1version 6.17-rc2version 6.17-rc3version 6.17-rc4version 6.17-rc5 and 1 moreversion 6.17-rc6 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.5 | CVSS 3.1 | Medium | 1.8 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 5.5 | CVSS 3.1 | Medium | — | — | GitHub, Inc. via GitHub Security Advisories |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- Affected products added · linux/linux kernel
- CVSS changed · 5.5
- Source status changed · → Analyzed
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 19, 2026 – Oct 19, 2026
- 1× Official description updated · Oct 19, 2026 – Oct 19, 2026
References
6 on the record
- git.kernel.org/stable/c/2cb17c88edd3a1c7aa6bc880dcdb35a6866fcb2e
- git.kernel.org/stable/c/d1f3db4e7a3be29fc17f01850f162363f919370d
- git.kernel.org/stable/c/8df354eb2dd63d111ed5ae2e956e0dbb22bcf93b
- git.kernel.org/stable/c/6b4be64fd9fec16418f365c2d8e47a7566e9eba5
- nvd.nist.gov/vuln/detail/CVE-2025-39947
- github.com/advisories/GHSA-r3wm-5qjq-c8qp
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-98866 sched/cache: Introduce task_struct->sched_cache_grp to fix UAF 1d
- Unknown CVE-2026-98867 dm-pcache: bound the logical key offset from persistent memory 1d
- Unknown CVE-2026-98868 dm-pcache: reject a kset that overruns its segment 1d
- Unknown CVE-2026-98856 kprobes: Skip disarmed probes when checking optkprobe overlap 1d
- Unknown CVE-2026-98857 ipvs: bound LBLCR and LBLC cache growth 1d
- Unknown CVE-2026-98858 io_uring: fix task_work add use-after-free with SQPOLL 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2025-39947 is "net/mlx5e: Harden uplink netdev access against device unbind", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.15% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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