CVE-2026-79607: Xenstore: Guests can crash xenstored during Live Update
Vulnerability summary
CVE-2026-79607 is a medium (CVSS 5.5) vulnerability in xen. EPSS estimates a 0.12% chance of exploitation in the next 30 days, higher than 2% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 13-10-2026PublishedVulnerability first disclosed.
- 16-10-2026Last modifiedVulnerability information updated.
Description
During Xenstore live update the state record for a Xenstore watch with specified watch depth is written with two bytes missing. This results in an inconsistent state when reading the state back in the new Xenstore, causing a crash of Xenstore or wrong Xenstore data.
CVSS metrics
3 scores · 3 sources · 1 version- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.12%
Chance of exploitation in the next 30 days
Percentile
2%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
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 causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- xenAll versions (No fix recorded)
Ubuntu1 product
- xenAll versions (No fix recorded)
2 vendors · 2 products
