VulnerabilityPublished 4 Sep 2026Updated 9 Oct 2026

CVE-2026-80873: Linux kernel · KVM: arm64: nv: Write ESR_EL2 for injected nested SError exceptions

Affects Linux kernelSource GCVE Database

Not known to be exploited · fixed in 7.0.0-1014.14~24.04.1 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:05 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 7.0.0-1014.14~24.04.1, 7.0.0-1017.17~24.04.1, 7.0.0-1016.16~24.04.1 +11

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-hw7g-293v-4f3g

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected <7.0.0-38.38	Fixed in 7.0.0-38.38
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected <7.0.0-1014.14	Fixed in 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected <7.0.0-1017.17	Fixed in 7.0.0-1017.17
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected <7.0.0-1016.16	Fixed in 7.0.0-1016.16
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected <7.0.0-1014.14	Fixed in 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected <7.0.0-1008.9	Fixed in 7.0.0-1008.9

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available and should be applied to affected Linux kernel versions to correct the ESR_EL2 handling for nested SError exceptions. The vendor advisory confirms that this issue has been fixed. Users running affected versions should update to the fixed kernel releases to mitigate this vulnerability.

Description

A vulnerability in the Linux kernel's KVM subsystem for ARM64 architecture was resolved. The issue involved the improper handling of ESR_EL2 register writes for injected nested SError exceptions, causing stale syndrome information to be observed by guest L2 hypervisors. This flaw affected specific Linux kernel versions and could impact nested virtualization environments. The vulnerability has been addressed with a patch that ensures ESR_EL2 is correctly written for SError exceptions.

Impact

The vulnerability could cause guest L2 hypervisors running nested virtualization on ARM64 to observe stale syndrome information for nested SError exceptions. While this does not directly indicate a remote exploit or privilege escalation, it may affect the correctness and reliability of nested virtualization exception handling, potentially leading to unexpected behavior in virtualized environments.

Summary

The Linux kernel's KVM module for ARM64 did not write the ESR_EL2 register for injected nested SError exceptions, unlike synchronous exceptions where ESR_EL2 is written. The function kvm_inject_el2_exception() omitted writing ESR_EL2 for SError, and enter_exception64() did not write ESR_ELx for any exception type, resulting in stale ESR_EL2 syndrome data being observed by guest L2 hypervisors. This affected both kvm_inject_nested_serror() and the EASE path in kvm_inject_nested_sea(). The patch modifies the code to write ESR_EL2 for except_type_serror, aligning it with except_type_sync behavior.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 25 Oct 2026, 04:12 UTC

Technical details

References

Community reviews

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