CVE-2021-28688
The lack of cleanup would result in leaking persistent grants.
Does this matter?
Lower severity and a low EPSS score (0.34%). Track it; it rarely justifies an emergency change on its own.
Description
The fix for XSA-365 includes initialization of pointers such that subsequent cleanup code wouldn't use uninitialized or stale values. This initialization went too far and may under certain conditions also overwrite pointers which are in need of cleaning up. The lack of cleanup would result in leaking persistent grants. The leak in turn would prevent fully cleaning up after a respective guest has died, leaving around zombie domains. All Linux versions having the fix for XSA-365 applied are vulnerable. XSA-365 was classified to affect versions back to at least 3.11.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
- EPSS
- 0.34% probability · 27th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-665
- Affected
- linux/linux kernel · debian/debian linux
- Source
- security@xen.org
EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://lists.debian.org/debian-lts-announce/2021/06/msg00019.htmlThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/06/msg00020.htmlThird Party Advisory
- https://xenbits.xenproject.org/xsa/advisory-371.txtPatch, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/06/msg00019.htmlThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/06/msg00020.htmlThird Party Advisory
- https://xenbits.xenproject.org/xsa/advisory-371.txtPatch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.