5.5

CVE-2021-26933: debian debian_linux

Modified
AliasesALPINE-CVE-2021-26933UBUNTU-CVE-2021-26933DEBIAN-CVE-2021-26933
Published 17-02-2021Last modified 03-08-2024

Vulnerability summary

CVE-2021-26933 is a medium (CVSS 5.5) vulnerability in debian debian_linux. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 25.8% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.33%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1
DSA-4888-1

Timeline

  1. 17-02-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

An issue was discovered in Xen 4.9 through 4.14.x. On Arm, a guest is allowed to control whether memory accesses are bypassing the cache. This means that Xen needs to ensure that all writes (such as the ones during scrubbing) have reached the memory before handing over the page to a guest. Unfortunately, the operation to clean the cache is happening before checking if the page was scrubbed. Therefore there is no guarantee when all the writes will reach the memory.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.33%

Chance of exploitation in the next 30 days

Percentile

26%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.33% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Debian2 products
Alpine1 product
  • xen≥ 4.9.0, < 4.13.2-r5 | ≥ 4.9.0, < 4.14.1-r2 | ≥ 4.9.0, < 4.14.1-r3
Fedoraproject1 product
Ubuntu1 product
  • xenAll versions (No fix recorded)
Xen1 product
  • xen≥ 4.9.0, ≤ 4.14.1

5 vendors · 6 products

References

10 links