Medium

CVE-2026-46290 — x86/efi: Fix graceful fault handling after FPU softirq changes

In the Linux kernel, the following vulnerability has been resolved: x86/efi: Fix graceful fault handling after FPU softirq changes Since commit d02198550423 ("x86/fpu: Improve crypto performance by making kernel-mode FPU reliably usable in softirqs"), kernel_fpu_begin() calls fpregs_lock() which uses local_bh_disable() instead of the previous preempt_disable(). This sets SOFTIRQ_OFFSET in preempt_count during the entire EFI runtime service call, causing in_interrupt() to return true in normal task context. The graceful page fault handler efi_crash_gracefully_on_page_fault() uses in_interrupt() to bail out for faults in real interrupt context. With SOFTIRQ_OFFSET now set, the handler always bails out, leaving EFI firmware page faults unhandled. This escalates to die() which also sees in_interrupt() as true and calls panic("Fatal exception in interrupt"), resulting in a hard system freeze. On systems with buggy firmware that triggers page faults during EFI runtime calls (e.g., accessing unmapped memory in GetTime()), this causes an unrecoverable hang instead of the expected graceful EFI_ABORTED recovery. Fix by replacing in_interrupt() with !in_task(). This preserves the original intent of bailing for interrupts or NMI faults, while no longer falsely triggering from the FPU code path's local_bh_disable(). [ardb: Sashiko spotted that using 'in_hardirq() || in_nmi()' leaves a window where a softirq may be taken before fpregs_lock() is called, but after efi_rts_work.efi_rts_id has been assigned, and any page faults occurring in that window will then be misidentified as having been caused by the firmware. Instead, use !in_task(), which incorporates in_serving_softirq(). ]

Published Jun 8, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1
Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.16%

ahead of 5% of scored CVEs · Oct 14, 2026

Affects

Linux

Linux and 1 more

CVSS base

5.5

Medium · 1 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ d02198550423a0b695e7a24ec77153209ad45b09 and < 22b365ba1af3d8c6036b8e5112fffe80998b85a0≥ d02198550423a0b695e7a24ec77153209ad45b09 and < db155b86d1523e85941f61efd7d7ffb594cc9a29≥ d02198550423a0b695e7a24ec77153209ad45b09 and < 088f65e206087bf903743bd18417261d7a4c9644version 6.15	Vulnerable	CVE Program (cve.org) e CISA ADP
Linux	Linux Kernel	≥ 6.15 and < 6.18.30≥ 6.19 and < 7.0.7version 7.1-rc1version 7.1-rc2	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
5.5	CVSS 3.1	Medium	1.8	3.6	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov)

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.16%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.

endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Affected products added · linux/linux
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 5.5
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Jun 8, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

3 on the record

git.kernel.org/stable/c/088f65e206087bf903743bd18417261d7a4c9644
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/db155b86d1523e85941f61efd7d7ffb594cc9a29
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/22b365ba1af3d8c6036b8e5112fffe80998b85a0
Patch, NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 12h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 12h
Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 1d
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-46290 is "x86/efi: Fix graceful fault handling after FPU softirq changes", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.16% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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