9.3

CVE-2023-53996: x86/sev: Make enc_dec_hypercall() accept a size instead of npages

Deferred
AliasesUBUNTU-CVE-2023-53996DEBIAN-CVE-2023-53996
Published 24-12-2025Last modified 05-08-2026

Vulnerability summary

CVE-2023-53996 is a critical (CVSS 9.3) vulnerability in linux. EPSS estimates a 0.11% chance of exploitation in the next 30 days, higher than 1.2% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.3 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.3/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.11%
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 15 · Related 12
RHSA-2023:7749RHSA-2024:0575RHSA-2024:3138SUSE-SU-2026:0263-1SUSE-SU-2026:0278-1SUSE-SU-2026:0281-1

Timeline

  1. 24-12-2025
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: x86/sev: Make enc_dec_hypercall() accept a size instead of npages enc_dec_hypercall() accepted a page count instead of a size, which forced its callers to round up. As a result, non-page aligned vaddrs caused pages to be spuriously marked as decrypted via the encryption status hypercall, which in turn caused consistent corruption of pages during live migration. Live migration requires accurate encryption status information to avoid migrating pages from the wrong perspective.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.11%

Chance of exploitation in the next 30 days

Percentile

1%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.11% 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, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu88 products
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
  • linux-aws-5.13All versions (No fix recorded)
  • linux-aws-5.19All versions (No fix recorded)
Debian1 product
  • linux< 6.1.55-1 | < 6.5.3-1
Linux1 product
  • linux≥ 064ce6c550a0630789978bfec7a13ab2bd1bdcdf, < ba50e7773a99a109a1ea6f753b766a080d3b21cc | ≥ 064ce6c550a0630789978bfec7a13ab2bd1bdcdf, < 6615212d8e131b45bd9705b0d69cc0d2f624666f | ≥ 064ce6c550a0630789978bfec7a13ab2bd1bdcdf, < 8ae7457e71a320867d868f2622d7c643596e4f43 | ≥ 064ce6c550a0630789978bfec7a13ab2bd1bdcdf, < ac3f9c9f1b37edaa7d1a9b908bc79d843955a1a2 | 5.16

3 vendors · 90 products

References

7 links