CVE-2026-62426: sysctl and platform-op locks open to abuse
Vulnerability summary
CVE-2026-62426 is a high (CVSS 8.8) Unrestricted Externally Accessible Lock vulnerability in xen. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12.5% of scored vulnerabilities.
Not severe (CVSS 8.8, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 6 · Related 6Timeline
- 28-07-2026PublishedVulnerability first disclosed.
- 28-07-2026Last modifiedVulnerability information updated.
Description
[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] To manage the system, sysctl and platform operations are used by the control domain or a possible Xenstore domain. Some of these operations may not be executed in parallel, so a system-wide lock each is used. The way those locks are acquired is, however, not providing any fairness. Furthermore, with XSM/Flask in use, the lock acquire will, for some operations, occur ahead of any permission checking. The sysctl issue is CVE-2026-62426. The platform-op issue is CVE-2026-62427.
CVSS metrics
5 scores · 5 sources · 1 version- OSV · AlpineEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST8.8HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.22%
Chance of exploitation in the next 30 days
Percentile
13%
Versus all other CVEs
30-day change
Decrease -0.15 pp
From 0.37% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-412Unrestricted Externally Accessible LockThe product properly checks for the existence of a lock, but the lock can be externally controlled or influenced by an actor that is outside of the intended sphere of control.
- CWE-667Improper LockingThe product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
Affected systems
Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Alpine1 product
- xen< 4.19.6-r0 | < 4.20.4-r0 | < 4.21.2-r0
Debian1 product
- xen< 4.17.7-0+deb12u1 | < 4.20.3+127-gc42374a105-0+deb13u1 | < 4.20.3+127-gc42374a105-1
Ubuntu1 product
- xenAll versions (No fix recorded)
3 vendors · 3 products
