In the Linux kernel, the following vulnerability has been resolved:
net: usb: aqc111: fix error handling of usbnet read calls
Syzkaller, courtesy of syzbot, identified an error (see report [1]) in
aqc111 driver, caused by incomplete sanitation of usb read calls'
results. This problem is quite similar to the one fixed in commit
920a9fa27e78 ("net: asix: add proper error handling of usb read errors").
For instance, usbnet_read_cmd() may read fewer than 'size' bytes,
even if the caller expected the full amount, and aqc111_read_cmd()
will not check its result properly. As [1] shows, this may lead
to MAC address in aqc111_bind() being only partly initialized,
triggering KMSAN warnings.
Fix the issue by verifying that the number of bytes read is
as expected and not less.
[1] Partial syzbot report:
BUG: KMSAN: uninit-value in is_valid_ether_addr include/linux/etherdevice.h:208 [inline]
BUG: KMSAN: uninit-value in usbnet_probe+0x2e57/0x4390 drivers/net/usb/usbnet.c:1830
is_valid_ether_addr include/linux/etherdevice.h:208 [inline]
usbnet_probe+0x2e57/0x4390 drivers/net/usb/usbnet.c:1830
usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x4d1/0xd90 drivers/base/dd.c:658
__driver_probe_device+0x268/0x380 drivers/base/dd.c:800
...
Uninit was stored to memory at:
dev_addr_mod+0xb0/0x550 net/core/dev_addr_lists.c:582
__dev_addr_set include/linux/netdevice.h:4874 [inline]
eth_hw_addr_set include/linux/etherdevice.h:325 [inline]
aqc111_bind+0x35f/0x1150 drivers/net/usb/aqc111.c:717
usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772
usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396
...
Uninit was stored to memory at:
ether_addr_copy include/linux/etherdevice.h:305 [inline]
aqc111_read_perm_mac drivers/net/usb/aqc111.c:663 [inline]
aqc111_bind+0x794/0x1150 drivers/net/usb/aqc111.c:713
usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772
usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
...
Local variable buf.i created at:
aqc111_read_perm_mac drivers/net/usb/aqc111.c:656 [inline]
aqc111_bind+0x221/0x1150 drivers/net/usb/aqc111.c:713
usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.1): severity, escalated by confirmed exploitation. This CVE's 7.1 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.1 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-26). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it