In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: property: Reject dir_len < 4 to prevent size_t underflow
On the non-root path, __tb_property_parse_dir() takes dir_len from
entry->length (u16 widened to size_t). Two distinct OOB conditions
follow when entry->length < 4:
- The non-root path begins with kmemdup(&block[dir_offset],
sizeof(*dir->uuid), ...) which always reads 4 dwords from
dir_offset. tb_property_entry_valid() only enforces
dir_offset + entry->length <= block_len, so a crafted entry
with dir_offset close to the end of the property block and
entry->length in 0..3 passes that gate but lets the UUID copy
run off the block (e.g. dir_offset = 497, dir_len = 3 in a
500-dword block reads block[497..501]).
- After the kmemdup, content_len = dir_len - 4 underflows size_t
to ~SIZE_MAX, nentries becomes SIZE_MAX / 4, and the entry
walk runs OOB on each iteration until an entry fails
validation or the kernel oopses on an unmapped page.
Reject dir_len < 4 on the non-root path *before* the UUID kmemdup,
which closes both holes.
Also move INIT_LIST_HEAD(&dir->properties) up to immediately after
the dir allocation so the new error-return path (and the existing
uuid-alloc failure path) calling tb_property_free_dir() sees a
walkable list rather than the zero-initialized NULL next/prev that
list_for_each_entry_safe() would oops on.
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 2026-10-29). 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