In the Linux kernel, the following vulnerability has been resolved:
powerpc64/ftrace: fix clobbered r15 during livepatching
While r15 is clobbered always with PPC_FTRACE_OUT_OF_LINE, it is
not restored in livepatch sequence leading to not so obvious fails
like below:
BUG: Unable to handle kernel data access on write at 0xc0000000000f9078
Faulting instruction address: 0xc0000000018ff958
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP: c0000000018ff958 LR: c0000000018ff930 CTR: c0000000009c0790
REGS: c00000005f2e7790 TRAP: 0300 Tainted: G K (6.14.0+)
MSR: 8000000000009033 CR: 2822880b XER: 20040000
CFAR: c0000000008addc0 DAR: c0000000000f9078 DSISR: 0a000000 IRQMASK: 1
GPR00: c0000000018f2584 c00000005f2e7a30 c00000000280a900 c000000017ffa488
GPR04: 0000000000000008 0000000000000000 c0000000018f24fc 000000000000000d
GPR08: fffffffffffe0000 000000000000000d 0000000000000000 0000000000008000
GPR12: c0000000009c0790 c000000017ffa480 c00000005f2e7c78 c0000000000f9070
GPR16: c00000005f2e7c90 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 c00000005f3efa80 c00000005f2e7c60 c00000005f2e7c88
GPR24: c00000005f2e7c60 0000000000000001 c0000000000f9078 0000000000000000
GPR28: 00007fff97960000 c000000017ffa480 0000000000000000 c0000000000f9078
...
Call Trace:
check_heap_object+0x34/0x390 (unreliable)
__mutex_unlock_slowpath.isra.0+0xe4/0x230
seq_read_iter+0x430/0xa90
proc_reg_read_iter+0xa4/0x200
vfs_read+0x41c/0x510
ksys_read+0xa4/0x190
system_call_exception+0x1d0/0x440
system_call_vectored_common+0x15c/0x2ec
Fix it by restoring r15 always.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.8 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 2026-11-06). 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, and whom BOD 26-04 binds: 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 (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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.
The score's inputs: 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