CriticalCVE-2025-10263

Arm C1-Ultra: Race Condition (CVE-2025-10263)

Published 09.06.2026Last modified 01.09.2026Sources: Debian LTS, Ubuntu, Red Hat, BSI, SingCERT, SUSE, Msrc Update Guide, CVE.org, Debian

What is affected, what to do

Arm C1-Ultra, C1-Premium, Neoverse V3 & V3AE, Neoverse V2, Neoverse V1, Neoverse-N2, Neoverse-N1, Cortex-X925, Cortex-X4, Cortex-X3, Cortex-X2, Cortex-X1 & X1C, Cortex-A710, Cortex-A78, A78AE & A78C, Cortex-A77, Cortex-A76 & A76A may allow writes to resources owned by a higher exception level.

The available sources name no fixed version. Check the vendor guidance in the references below.

Affected: Arm C1-Ultra eq 0..0
Arm C1-Premium eq 0..0
Arm Neoverse V3 eq 0..0
Arm Neoverse V3AE eq 0..0
Arm Neoverse V1 eq 0..0
Arm Neoverse N2 eq 0..0
Arm Neoverse N1 eq 0..0
Arm Cortex-X925 eq 0..0
Arm Cortex-X4 eq 0..0
Arm Cortex-X3 eq 0..0
Arm Cortex-X2 eq 0..0
Arm Cortex-X1 eq 0..0
Arm Cortex-X1C eq 0..0
Arm Cortex-A710 eq 0..0
Arm Cortex-A78 eq 0..0
Arm Cortex-A78AE eq 0..0
Arm Cortex-A78C eq 0..0
Arm Cortex-A77 eq 0..0
Arm Cortex-A76 eq 0..0
Arm Cortex-A76AE eq 0..0

Not sure whether and how you are affected? Ask a question about this vulnerability

Metrics

9.3

Priority

XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

Source: Vendor (CNA), CVSS v3

9.3

CVSS v3

Severity Critical on the scale from 0 to 10.

Source: Debian LTS, Ubuntu, Red Hat, BSI, SingCERT, SUSE, Msrc Update Guide, CVE.org, Debian

0.5 %

EPSS score

Low — model estimates < 1% exploitation likelihood.

Source: FIRST EPSS, percentile 45.4

Show all metrics

Severity: Critical
Priority (0–325) The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first? Read in glossary: 81.72 Methodology
Exploit maturity An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack. Read in glossary: no public PoC known
XIEM Effective CVSS XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command. Read in glossary: 9.3 Methodology
CVSS v3 CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions. Read in glossary: 9.3
EPSS score The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“. Read in glossary: 0.5 %; Low — model estimates < 1% exploitation likelihood.
EPSS percentile The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking. Read in glossary: 45.4; High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
KEV status The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching. Read in glossary: —
Published: 09.06.2026
CWE CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect. Read in glossary: CWE-362

Detection rules

No NEOSEC detection rule is available for this vulnerability yet.

Classification under NIS2 and CRA

Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

NIS2 NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management. Read in glossary: High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates. Read in glossary: From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001 ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security. Read in glossary: Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

Description

Source: Debian LTS Advisories, Ubuntu Security Notices, redhat_csaf, BSI WID Portal, BSI CSAF, CSA/SingCERT, suse_csaf, Microsoft Security Update Guide, cvelistv5, NVD (NIST), Debian Security Advisories, CVE.org (MITRE)

Affected products

The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

Affected products
		Affected versions	Fixed in
Arm	C1-Premium	`0`	—
Arm	C1-Ultra	`0`	—
Arm	Cortex-A710	`0`	—
Arm	Cortex-A76	`0`	—
Arm	Cortex-A76AE	`0`	—
Arm	Cortex-A77	`0`	—
Arm	Cortex-A78	`0`	—
Arm	Cortex-A78AE	`0`	—
Arm	Cortex-A78C	`0`	—
Arm	Cortex-X1	`0`	—
Arm	Cortex-X1C	`0`	—
Arm	Cortex-X2	`0`	—
Arm	Cortex-X3	`0`	—
Arm	Cortex-X4	`0`	—
Arm	Cortex-X925	`0`	—
Arm	Neoverse N1	`0`	—
Arm	Neoverse N2	`0`	—
Arm	Neoverse V1	`0`	—
Arm	Neoverse V3	`0`	—
Arm	Neoverse V3AE	`0`	—
AMD	Prozessor	`Versal AI Edge Series Gen 2` `EPYC` `Versal Prime Series Gen 2`	— — —
IBM	QRadar SIEM	`<7.5.0 UP15 IF06`	—
Open Source	Xen	`Arm`	—

Vendors and products

Affected operating systems

Affected operating systems

Linux	debian	linux	`bookworm`
Linux	debian	linux	`bullseye`
Linux	ubuntu	linux	`noble`
Linux	debian	linux-6.1	`bullseye`
Linux	ubuntu	linux-azure	`noble`
Linux	ubuntu	linux-azure-6.8	`jammy`
Linux	ubuntu	linux-azure-fde	`noble`
Linux	ubuntu	linux-azure-fde-6.8	`jammy`
Linux	ubuntu	linux-azure-fips	`noble`
Linux	ubuntu	linux-fips	`noble`
Linux	ubuntu	linux-gcp	`noble`
Linux	ubuntu	linux-gcp-6.8	`jammy`
Linux	ubuntu	linux-gcp-fips	`noble`
Linux	ubuntu	linux-gke	`noble`
Linux	ubuntu	linux-gkeop	`noble`
Linux	ubuntu	linux-ibm	`noble`
Linux	ubuntu	linux-lowlatency	`noble`
Linux	ubuntu	linux-lowlatency-hwe-6.8	`jammy`
Linux	ubuntu	linux-oracle	`noble`
Linux	ubuntu	linux-oracle-6.8	`jammy`
Linux	ubuntu	linux-raspi	`noble`
Linux	ubuntu	linux-raspi-realtime	`noble`
Linux	ubuntu	linux-realtime	`noble`
Linux	ubuntu	linux-realtime-6.8	`jammy`

Weakness classes (CWE)

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Class
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
Entry at MITRE CWE-362

References & sources

developer.arm.comdocumentation/112137
xenbits.xen.orgxsa/advisory-493.html
openwall.comlists/oss-security/2026/06/09/13
access.redhat.comsecurity/cve/CVE-2025-10263Vulnerability database, x_refsource_REDHAT
bugzilla.redhat.comRHBZ#2486958Issue tracking, x_refsource_REDHAT
security.access.redhat.comdata/csaf/v2/vex/2025/cve-2025-10263.jsonx_sadp-csaf-vex
access.redhat.comerrata/RHSA-2026:40764Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:34911Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:51603Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:49031Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:36018Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:36349Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:47248Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:49033Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:36348Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:51604Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:51746Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:52649Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:54599Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:55445Vendor advisory, x_refsource_REDHAT

Changes to this CVE

Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

01.09.2026Record modifiedRed Hat ADP

1 individual change: Affected versions (publisher)

Show the original change

Individual changes of this event as published by NVD
Type	Action	Before	After
Affected versions (publisher)	added	—	Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2025/10xxx/CVE-2025-10263.json">CVE-2025-10263</a>

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

31.08.2026Record modifiedRed Hat ADP

New references:

Show 4 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Affected versions (publisher)	added	—	Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2025/10xxx/CVE-2025-10263.json">CVE-2025-10263</a>
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:56786
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:56853
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:56911

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

21.08.2026Record modifiedRed Hat ADP

New references:

Show 3 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:54187
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:54205
Affected versions (publisher)	changed	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8 (+23)	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8 (+25)

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

20.08.2026Record modifiedRed Hat ADP

New references:

Show 3 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:54544
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:54553
Affected versions (publisher)	changed	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8 (+21)	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8 (+23)

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

19.08.2026Record modifiedRed Hat ADP

New references:

https://access.redhat.com/errata/RHSA-2026:54581

Show 2 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:54581
Affected versions (publisher)	changed	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8 (+19)	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8 (+21)

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Show 5 older changes

18.08.2026Record modifiedRed Hat ADP
New references:
- https://access.redhat.com/errata/RHSA-2026:54599
Show the original change
Individual changes of this event as published by NVD
Type Action Before After
Reference added
—
https://access.redhat.com/errata/RHSA-2026:54599
Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:54599

10.08.2026Record modifiedRed Hat ADP

New references:

Show 3 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:51746
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:52649
Affected versions (publisher)	changed	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 8 (+13)	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 8 (+16)

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

03.08.2026Record modifiedRed Hat ADP

New references:

Show 3 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:49031
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:49033
Affected versions (publisher)	changed	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 8 (+10)	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 8 (+13)

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

22.07.2026Record modifiedRed Hat ADP

New references:

https://access.redhat.com/errata/RHSA-2026:40764

Show 2 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:40764
Affected versions (publisher)	changed	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 8 (+8)	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 8 (+8)

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

03.07.2026Record modifiedRed Hat ADP

New references:

https://access.redhat.com/errata/RHSA-2026:34911

Show 2 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:34911
Affected versions (publisher)	changed	Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 (+4)	Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) (+9)

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

One NVD translation into another language is hidden.

Linked advisories

@RISK®: The Consensus Security Vulnerability Alert: Vol. 26, Num. 24SANS @RISK18.06.2026

Embed badge

Show the severity and KEV status of this vulnerability on your site – with a link back here. The image is updated hourly.

<a href="https://intel.neosec.eu/en/cve/CVE-2025-10263"><img src="https://intel.neosec.eu/badge/cve/CVE-2025-10263.svg?lang=en" alt="CVE-2025-10263 – NEOSEC Intel" height="20"></a>