NVD / CVE Program· CNA Linux

CVE-2026-89981: arm64: Don't read GMID_EL1 when MTE is disabled

Noroxi assessment

Priority: Monitor (action score 0/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.19% (FIRST EPSS).
Fixed version: Linux Linux 5445d64199626974269fcdf347769ad44b0bb53b, d2d22ff377cd43f2e9660426ff22e3cd4c534637.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 5445d64199626974269fcdf347769ad44b0bb53b, d2d22ff377cd43f2e9660426ff22e3cd4c534637 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: arm64: Don't read GMID_EL1 when MTE is disabled __cpuinfo_store_cpu() gates the GMID_EL1 read on the raw ID_AA64PFR1_EL1, so it reads the register even when the kernel has disabled MTE (CONFIG_ARM64_MTE=n or arm64.nomte). KVM sets HCR_EL2.TID5 in that case, and pKVM injects an UNDEF the host cannot handle: Internal error: Oops - Undefined instruction: 0000000002000000 [#1] SMP pc : __cpuinfo_store_cpu+0xf4/0x264 Kernel panic - not syncing: Attempted to kill the idle task! Only pKVM reaches it, and only after a CPU is offlined and brought back online: its CPU_ON relay sets the host HCR before the CPU enters EL1, while plain nVHE sets it at CPUHP_AP_KVM_ONLINE. Gate the read on the CPU's own ID_AA64PFR1_EL1 with the command-line override applied, and on CONFIG_ARM64_MTE, which no register reflects. The boot CPU stores its registers before init_cpu_features() strips an unsafe override, so clamp against the hardware value here too.

—No exploit Fix available

EUVD-2026-80581

Published: Sep 16, 2026
Updated: Oct 19, 2026
EPSS: 0.1% · 9th percentile
CWE: —

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Action score

Monitor

Low priority for now.

CVSS: 0 / 40 · —
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 7.0affected
- f35abcbb8a084db4c24b66ccc8db0405c08e2f61 and later · before d2d22ff377cd43f2e9660426ff22e3cd4c534637affected · git
- f35abcbb8a084db4c24b66ccc8db0405c08e2f61 and later · before 5445d64199626974269fcdf347769ad44b0bb53baffected · git
- before 7.0not affected · semver
- 7.2.5 and later · up to and including 7.2.*not affected · semver
- 7.3 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:14	linux	before 7.2.6-1	7.2.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
40Plan
CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
40Plan
CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
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Published before and after this one in the same product

← EarlierCVE-2026-89979Sep 16, 2026 · ALSA: pcm: Fix race between non-atomic ops and trigger-start
31Monitor
← EarlierCVE-2026-89980Sep 16, 2026 · ALSA: harmony: initialize locks before requesting IRQ
33Monitor
Later →CVE-2026-89982Sep 16, 2026 · i2c: mux: Fix channel node leak on adapter add failure
0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	5445d64199626974269fcdf347769ad44b0bb53b	Vendor (CNA)
Linux Linux	d2d22ff377cd43f2e9660426ff22e3cd4c534637	Vendor (CNA)
debian:linux	7.2.6-1 · Debian:14	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).