In the Linux kernel, the following vulnerability has been resolved:
usb: typec: tcpm: bound altmode_desc[] per iteration in svdm_consume_modes()
svdm_consume_modes() checks pmdata->altmodes against the array size once
before the loop over the count, but forgot to check the bound at every
point in the loop.
In the well-behaved SVDM discovery flow this is harmless because each of
at most SVID_DISCOVERY_MAX SVIDs contributes at most MODE_DISCOVERY_MAX
modes, exactly filling altmode_desc[ALTMODE_DISCOVERY_MAX]. But the
CMDT_RSP_ACK handler in tcpm_pd_svdm() does not correlate an incoming
ACK with any request the port actually sent. Once port->partner is set,
an unsolicited Discover Modes ACK is consumed unconditionally. A broken
or malicious port partner can therefore drive altmodes to
ALTMODE_DISCOVERY_MAX - 1 via the normal flow, and then send one extra
Discover Modes ACK with seven VDOs. Because the pre-loop check passes,
the loop could then writes up to five entries past altmode_desc[]. For
mode_data_prime the next field in struct tcpm_port is the
partner_altmode[] pointer array, which then receives partner-chosen
SVID/VDO bytes.
Move the bound check inside the loop so the array can never be indexed
past ALTMODE_DISCOVERY_MAX regardless of how many VDOs the partner
supplies or how the function was reached.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
- EG Severity
- Not assessed: no CVSS publishedA missing CVSS is not a severity of zero.
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). 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
- No SSVC decision: EchelonGraph has not assessed this CVECISA 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: the BOD 26-04 block below.
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.
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