CVE-2026-72391 — net: phy: sfp: free mii_bus in sfp_i2c_mdiobus_destroy
In the Linux kernel, the following vulnerability has been resolved: net: phy: sfp: free mii_bus in sfp_i2c_mdiobus_destroy sfp_i2c_mdiobus_create() allocates the I2C MDIO bus with mdio_i2c_alloc(), a plain (non-devm) allocation, and registers it. sfp_i2c_mdiobus_destroy() only unregisters the bus and clears sfp->i2c_mii without calling mdiobus_free(). As the only reference to the bus is then cleared, the struct mii_bus is leaked. This is hit whenever a copper/RollBall SFP module that instantiated an MDIO bus is removed: sfp_sm_main() takes the global teardown path and calls sfp_i2c_mdiobus_destroy(). sfp_cleanup(), on driver unbind, frees sfp->i2c_mii directly, which is why the leak only triggered on module hot-removal and not on unbind. Free the bus in sfp_i2c_mdiobus_destroy() to match the allocation done in sfp_i2c_mdiobus_create().
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 0.2% (30-day exploitation probability)+2
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.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
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).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ e85b1347ace677c3822c12d9332dfaaffe594da6 and < 92dd9a522f01ef57f633a8c1953cf6d48ef2bcd5≥ e85b1347ace677c3822c12d9332dfaaffe594da6 and < d2c37f26d1a37f8177be5f354537f8ee3ec31cc2≥ e85b1347ace677c3822c12d9332dfaaffe594da6 and < 3183b6f5510c876a1c4b4a6bdc3d0ad8940fe742≥ e85b1347ace677c3822c12d9332dfaaffe594da6 and < 86d379fcf1b79bdf4bc2ac891297f30f63d041d8≥ e85b1347ace677c3822c12d9332dfaaffe594da6 and < 2381bf3f484e8e4fd89a225445872ec14e036ab5≥ e85b1347ace677c3822c12d9332dfaaffe594da6 and < 8f31efff9206f9f0adb853cad6916086aac4d5efversion 6.1 | Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 29, 2026 · 14 reading(s) · max 0.22%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
6 on the record
- git.kernel.org/stable/c/86d379fcf1b79bdf4bc2ac891297f30f63d041d8
- git.kernel.org/stable/c/2381bf3f484e8e4fd89a225445872ec14e036ab5
- git.kernel.org/stable/c/3183b6f5510c876a1c4b4a6bdc3d0ad8940fe742
- git.kernel.org/stable/c/8f31efff9206f9f0adb853cad6916086aac4d5ef
- git.kernel.org/stable/c/d2c37f26d1a37f8177be5f354537f8ee3ec31cc2
- git.kernel.org/stable/c/92dd9a522f01ef57f633a8c1953cf6d48ef2bcd5
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 2d
- Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 2d
- Unknown CVE-2026-99214 drm/vc4: hdmi: Move packet RAM enable to PM runtime 2d
- Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 2d
- Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 2d
- Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 2d
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 CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- 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-2026-72391 is "net: phy: sfp: free mii_bus in sfp_i2c_mdiobus_destroy", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.22% 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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