In the Linux kernel, the following vulnerability has been resolved:
um: Fix out-of-bounds read in LDT setup
syscall_stub_data() expects the data_count parameter to be the number of
longs, not bytes.
==================================================================
BUG: KASAN: stack-out-of-bounds in syscall_stub_data+0x70/0xe0
Read of size 128 at addr 000000006411f6f0 by task swapper/1
CPU: 0 PID: 1 Comm: swapper Not tainted 5.18.0+ #18
Call Trace:
show_stack.cold+0x166/0x2a7
__dump_stack+0x3a/0x43
dump_stack_lvl+0x1f/0x27
print_report.cold+0xdb/0xf81
kasan_report+0x119/0x1f0
kasan_check_range+0x3a3/0x440
memcpy+0x52/0x140
syscall_stub_data+0x70/0xe0
write_ldt_entry+0xac/0x190
init_new_ldt+0x515/0x960
init_new_context+0x2c4/0x4d0
mm_init.constprop.0+0x5ed/0x760
mm_alloc+0x118/0x170
0x60033f48
do_one_initcall+0x1d7/0x860
0x60003e7b
kernel_init+0x6e/0x3d4
new_thread_handler+0x1e7/0x2c0
The buggy address belongs to stack of task swapper/1
and is located at offset 64 in frame:
init_new_ldt+0x0/0x960
This frame has 2 objects:
[32, 40) 'addr'
[64, 80) 'desc'
==================================================================
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
- 0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). 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