In the Linux kernel, the following vulnerability has been resolved:
usb: atm: cxacru: fix endpoint checking in cxacru_bind()
Syzbot is still reporting quite an old issue [1] that occurs due to
incomplete checking of present usb endpoints. As such, wrong
endpoints types may be used at urb sumbitting stage which in turn
triggers a warning in usb_submit_urb().
Fix the issue by verifying that required endpoint types are present
for both in and out endpoints, taking into account cmd endpoint type.
Unfortunately, this patch has not been tested on real hardware.
[1] Syzbot report:
usb 1-1: BOGUS urb xfer, pipe 1 != type 3
WARNING: CPU: 0 PID: 8667 at drivers/usb/core/urb.c:502 usb_submit_urb+0xed2/0x18a0 drivers/usb/core/urb.c:502
Modules linked in:
CPU: 0 PID: 8667 Comm: kworker/0:4 Not tainted 5.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
RIP: 0010:usb_submit_urb+0xed2/0x18a0 drivers/usb/core/urb.c:502
...
Call Trace:
cxacru_cm+0x3c0/0x8e0 drivers/usb/atm/cxacru.c:649
cxacru_card_status+0x22/0xd0 drivers/usb/atm/cxacru.c:760
cxacru_bind+0x7ac/0x11a0 drivers/usb/atm/cxacru.c:1209
usbatm_usb_probe+0x321/0x1ae0 drivers/usb/atm/usbatm.c:1055
cxacru_usb_probe+0xdf/0x1e0 drivers/usb/atm/cxacru.c:1363
usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:517 [inline]
really_probe+0x23c/0xcd0 drivers/base/dd.c:595
__driver_probe_device+0x338/0x4d0 drivers/base/dd.c:747
driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:777
__device_attach_driver+0x20b/0x2f0 drivers/base/dd.c:894
bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427
__device_attach+0x228/0x4a0 drivers/base/dd.c:965
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487
device_add+0xc2f/0x2180 drivers/base/core.c:3354
usb_set_configuration+0x113a/0x1910 drivers/usb/core/message.c:2170
usb_generic_driver_probe+0xba/0x100 drivers/usb/core/generic.c:238
usb_probe_device+0xd9/0x2c0 drivers/usb/core/driver.c:293
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-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 2026-10-25). 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 every mission impact level.CISA BOD 26-04: 60 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 every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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)60 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 Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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