4.7

CVE-2023-46836: x86: BTC/SRSO fixes not fully effective

Modified
AliasesALPINE-CVE-2023-46836UBUNTU-CVE-2023-46836DEBIAN-CVE-2023-46836
Published 05-01-2024Last modified 04-11-2025

Vulnerability summary

CVE-2023-46836 is a medium (CVSS 4.7) vulnerability in xen. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 16.3% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 4.7, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
4.7/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.25%
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 8 · Related 8
OPENSUSE-SU-2024:13442-1SUSE-SU-2023:4466-1SUSE-SU-2023:4475-1SUSE-SU-2023:4476-1SUSE-SU-2023:4484-1SUSE-SU-2023:4485-1

Timeline

  1. 05-01-2024
    PublishedVulnerability first disclosed.
  2. 04-11-2025
    Last modifiedVulnerability information updated.

Description

The fixes for XSA-422 (Branch Type Confusion) and XSA-434 (Speculative Return Stack Overflow) are not IRQ-safe. It was believed that the mitigations always operated in contexts with IRQs disabled. However, the original XSA-254 fix for Meltdown (XPTI) deliberately left interrupts enabled on two entry paths; one unconditionally, and one conditionally on whether XPTI was active. As BTC/SRSO and Meltdown affect different CPU vendors, the mitigations are not active together by default. Therefore, there is a race condition whereby a malicious PV guest can bypass BTC/SRSO protections and launch a BTC/SRSO attack against Xen.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.25%

Chance of exploitation in the next 30 days

Percentile

16%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.25% 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.

Alpine1 product
  • xen< 4.15.5-r3 | < 4.16.5-r4 | < 4.17.2-r4
Debian1 product
  • xen< 4.17.2+76-ge1f9cb16e2-1~deb12u1 | < 4.17.2+76-ge1f9cb16e2-1
Ubuntu1 product
  • xenAll versions (No fix recorded)

3 vendors · 3 products

References

7 links