In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: bound copy_lcns dp->page_lcns[] index in analysis pass
In log_replay()'s analysis pass, after find_dp() returns a
valid DIR_PAGE_ENTRY for the (target_attr, target_vcn) tuple,
the copy_lcns block walks lrh->lcns_follow further entries:
t16 = le16_to_cpu(lrh->lcns_follow);
for (i = 0; i < t16; i++) {
size_t j = (size_t)(le64_to_cpu(lrh->target_vcn) -
le64_to_cpu(dp->vcn));
dp->page_lcns[j + i] = lrh->page_lcns[i];
}
find_dp() only validates that target_vcn falls within
[dp->vcn, dp->vcn + dp->lcns_follow), i.e., that the FIRST
cluster is covered. The walk through the further entries is
not bounded against dp->lcns_follow. For a malformed LRH
where target_vcn = dp->vcn + dp->lcns_follow - 1 and
lrh->lcns_follow > 1, the i > 0 writes overflow the dp's
allocated page_lcns[] array.
Add the missing j + lrh->lcns_follow <= dp->lcns_follow guard.
Reproduced under UML+KASAN on mainline 8d90b09e6741 as a
slab-out-of-bounds write of size 8 from log_replay+0x68d4 on
the mount path.
This is distinct from Pavitra Jha's 2026-05-02 patch
("fs/ntfs3: validate lcns_follow in log_replay conversion",
<[email protected]>) which
addresses the separate version-0 dirty-page-table conversion
path's memmove(&dp->vcn, ...) call. The two fixes are
complementary; both should land.
[[email protected]: clang-formatted the changes,
fixed conflicts]
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (8.4): severity, escalated by confirmed exploitation. This CVE's 8.4 is its impact severity (EG Severity), not escalated.
- EG Severity
- 8.4 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 2026-10-17). 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: 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 (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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)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 Vulnrichment) · Technical impact total (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