Every CVE Search/ Get API key

CVE-2023-46836

x86: BTC/SRSO fixes not fully effective

4.7 MediumFix available

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.

Attack profile

How easy it is to exploit

Attack vector
Local
Complexity
High
Privileges needed
Low
User interaction
None

What an attacker can affect

Confidentiality
High
Integrity
None
Availability
None

Exploit likelihood

0.25%Up 0.2 points since Jan 10, 2024
90%50%10%1%

What each source reports

NVD Score used 4.7

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.

Record
CVE-2023-46836
CVSS 3.1
4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Updated
2026-11-02
CVE List 4.7

x86: BTC/SRSO fixes not fully effective

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.

Record
CVE-2023-46836
CVSS 3.1
4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Updated
2026-11-02
EUVDEUVD-2023-51002 4.7

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.

Record
EUVD-2023-51002
CVSS 3.1
4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Updated
2026-11-02
GitHub AdvisoriesGHSA-4rmw-8gh7-w6g3 4.7

The fixes for XSA-422 (Branch Type Confusion) and XSA-434 (Speculative Return Stack Overflow) are...

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.

Record
GHSA-4rmw-8gh7-w6g3
CVSS 3.1
4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Updated
2026-11-02
OSVALPINE-CVE-2023-46836 4.7

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.

Record
ALPINE-CVE-2023-46836
CVSS 3.1
4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Updated
2026-11-02
OSV 4.7

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.

Record
CVE-2023-46836
CVSS 3.1
4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Updated
2026-11-02
Show 10 moreShow less
OSVDEBIAN-CVE-2023-46836 4.7

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.

Record
DEBIAN-CVE-2023-46836
CVSS 3.1
4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Updated
2026-11-02
OSVUBUNTU-CVE-2023-46836 4.7

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.

Record
UBUNTU-CVE-2023-46836
CVSS 3.1
4.7 MediumCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Updated
2026-11-02
OSVopenSUSE-SU-2024:13442-1 No score

xen-4.18.0_02-1.1 on GA media

These are all security issues fixed in the xen-4.18.0_02-1.1 package on the GA media of openSUSE Tumbleweed.

Record
openSUSE-SU-2024:13442-1
Updated
2026-11-02
OSVSUSE-SU-2023:4466-1 No score

Security update for xen

This update for xen fixes the following issues:

  • CVE-2023-46835: x86/AMD: mismatch in IOMMU quarantine page table levels (XSA-445) (bsc#1216654).
  • CVE-2023-46836: x86: BTC/SRSO fixes not fully effective (XSA-446) (bsc#1216807).
Record
SUSE-SU-2023:4466-1
Updated
2026-11-02
OSVSUSE-SU-2023:4475-1 No score

Security update for xen

This update for xen fixes the following issues:

  • CVE-2023-20588: AMD CPU transitional execution leak via division by zero (XSA-439) (bsc#1215474).

  • CVE-2023-34322: top-level shadow reference dropped too early for 64-bit PV guests (XSA-438) (bsc#1215145).

  • CVE-2023-34325: Multiple vulnerabilities in libfsimage disk handling (XSA-443) (bsc#1215747).

  • CVE-2023-34326: x86/AMD: missing IOMMU TLB flushing (XSA-442) (bsc#1215746).

  • CVE-2023-34327,CVE-2023-34328: x86/AMD: Debug Mask handling (XSA-444) (bsc#1215748).

  • CVE-2023-46835: x86/AMD: mismatch in IOMMU quarantine page table levels (XSA-445) (bsc#1216654).

  • CVE-2023-46836: x86: BTC/SRSO fixes not fully effective (XSA-446) (bsc#1216807).

  • Upstream bug fixes (bsc#1027519)

Record
SUSE-SU-2023:4475-1
Updated
2026-11-02
OSVSUSE-SU-2023:4476-1 No score

Security update for xen

This update for xen fixes the following issues:

  • CVE-2023-20588: AMD CPU transitional execution leak via division by zero (XSA-439) (bsc#1215474).

  • CVE-2023-34322: top-level shadow reference dropped too early for 64-bit PV guests (XSA-438) (bsc#1215145).

  • CVE-2023-34325: Multiple vulnerabilities in libfsimage disk handling (XSA-443) (bsc#1215747).

  • CVE-2023-34326: x86/AMD: missing IOMMU TLB flushing (XSA-442) (bsc#1215746).

  • CVE-2023-34327,CVE-2023-34328: x86/AMD: Debug Mask handling (XSA-444) (bsc#1215748).

  • CVE-2023-46835: x86/AMD: mismatch in IOMMU quarantine page table levels (XSA-445) (bsc#1216654).

  • CVE-2023-46836: x86: BTC/SRSO fixes not fully effective (XSA-446) (bsc#1216807).

  • Upstream bug fixes (bsc#1027519)

Record
SUSE-SU-2023:4476-1
Updated
2026-11-02
OSVSUSE-SU-2023:4484-1 No score

Security update for xen

This update for xen fixes the following issues:

  • CVE-2023-46835: x86/AMD: mismatch in IOMMU quarantine page table levels (XSA-445) (bsc#1216654).
  • CVE-2023-46836: x86: BTC/SRSO fixes not fully effective (XSA-446) (bsc#1216807).
Record
SUSE-SU-2023:4484-1
Updated
2026-11-02
OSVSUSE-SU-2023:4485-1 No score

Security update for xen

This update for xen fixes the following issues:

  • CVE-2023-46835: x86/AMD: mismatch in IOMMU quarantine page table levels (XSA-445) (bsc#1216654).
  • CVE-2023-46836: x86: BTC/SRSO fixes not fully effective (XSA-446) (bsc#1216807).
Record
SUSE-SU-2023:4485-1
Updated
2026-11-02
OSVSUSE-SU-2023:4486-1 No score

Security update for xen

This update for xen fixes the following issues:

  • CVE-2023-46835: x86/AMD: mismatch in IOMMU quarantine page table levels (XSA-445) (bsc#1216654).
  • CVE-2023-46836: x86: BTC/SRSO fixes not fully effective (XSA-446) (bsc#1216807).
Record
SUSE-SU-2023:4486-1
Updated
2026-11-02
OSVSUSE-SU-2023:4945-1 No score

Security update for xen

This update for xen fixes the following issues:

  • CVE-2023-46836: Fixed BTC/SRSO fixes not fully effective (bsc#1216807).
  • CVE-2023-46835: Fixed mismatch in IOMMU quarantine page table levels on x86/AMD (bsc#1216654).

Update to Xen 4.17.3 bug fix release (bsc#1027519).

Record
SUSE-SU-2023:4945-1
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
xen
Alpine:v3.15
 before 4.15.5-r3
4.15.5-r3
xen
Alpine:v3.16
 before 4.16.5-r4
4.16.5-r4
xen
Alpine:v3.17
 before 4.16.5-r4
4.16.5-r4
xen
Alpine:v3.18
 before 4.17.2-r4
4.17.2-r4
xen
Alpine:v3.19
 before 4.17.2-r4
4.17.2-r4
xen
Alpine:v3.20
 before 4.17.2-r4
4.17.2-r4
xen
Alpine:v3.21
 before 4.17.2-r4
4.17.2-r4
xen
Alpine:v3.22
 before 4.17.2-r4
4.17.2-r4
xen
Alpine:v3.23
 before 4.17.2-r4
4.17.2-r4
xen
Alpine:v3.24
 before 4.17.2-r4
4.17.2-r4
Show 43 moreShow less
Affected packages
PackageAffectedFixed
xen
Debian:12
 before 4.17.2+76-ge1f9cb16e2-1~deb12u1, plus listed versions
4.17.1+2-gb773c48e36-14.17.2+55-g0b56bed864-14.17.2-1
4.17.2+76-ge1f9cb16e2-1~deb12u1
xen
Debian:13
 before 4.17.2+76-ge1f9cb16e2-1
4.17.2+76-ge1f9cb16e2-1
xen
Debian:14
 before 4.17.2+76-ge1f9cb16e2-1
4.17.2+76-ge1f9cb16e2-1
xen
SUSE:Linux Enterprise High Performance Computing 15 SP3-ESPOS
From an advisory covering 2 CVEs
 before 4.14.6_08-150300.3.60.1
4.14.6_08-150300.3.60.1
xen
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSS
From an advisory covering 2 CVEs
 before 4.14.6_08-150300.3.60.1
4.14.6_08-150300.3.60.1
xen
SUSE:Linux Enterprise Server 15 SP3-LTSS
From an advisory covering 2 CVEs
 before 4.14.6_08-150300.3.60.1
4.14.6_08-150300.3.60.1
xen
SUSE:Linux Enterprise Server for SAP Applications 15 SP3
From an advisory covering 2 CVEs
 before 4.14.6_08-150300.3.60.1
4.14.6_08-150300.3.60.1
xen
SUSE:Linux Enterprise Micro 5.1
From an advisory covering 2 CVEs
 before 4.14.6_08-150300.3.60.1
4.14.6_08-150300.3.60.1
xen
SUSE:Linux Enterprise Micro 5.2
From an advisory covering 2 CVEs
 before 4.14.6_08-150300.3.60.1
4.14.6_08-150300.3.60.1
xen
SUSE:Enterprise Storage 7.1
From an advisory covering 2 CVEs
 before 4.14.6_08-150300.3.60.1
4.14.6_08-150300.3.60.1
xen
SUSE:Linux Enterprise Micro 5.5
From an advisory covering 8 CVEs
 before 4.17.2_08-150500.3.15.1
4.17.2_08-150500.3.15.1
xen
SUSE:Linux Enterprise Module for Basesystem 15 SP5
From an advisory covering 8 CVEs
 before 4.17.2_08-150500.3.15.1
4.17.2_08-150500.3.15.1
xen
SUSE:Linux Enterprise Module for Server Applications 15 SP5
From an advisory covering 8 CVEs
 before 4.17.2_08-150500.3.15.1
4.17.2_08-150500.3.15.1
xen
openSUSE:Leap 15.5
From an advisory covering 8 CVEs
 before 4.17.2_08-150500.3.15.1
4.17.2_08-150500.3.15.1
xen
SUSE:Linux Enterprise Micro 5.3
From an advisory covering 8 CVEs
 before 4.16.5_08-150400.4.40.1
4.16.5_08-150400.4.40.1
xen
SUSE:Linux Enterprise Micro 5.4
From an advisory covering 8 CVEs
 before 4.16.5_08-150400.4.40.1
4.16.5_08-150400.4.40.1
xen
SUSE:Linux Enterprise Module for Basesystem 15 SP4
From an advisory covering 8 CVEs
 before 4.16.5_08-150400.4.40.1
4.16.5_08-150400.4.40.1
xen
SUSE:Linux Enterprise Module for Server Applications 15 SP4
From an advisory covering 8 CVEs
 before 4.16.5_08-150400.4.40.1
4.16.5_08-150400.4.40.1
xen
openSUSE:Leap Micro 5.3
From an advisory covering 8 CVEs
 before 4.16.5_08-150400.4.40.1
4.16.5_08-150400.4.40.1
xen
openSUSE:Leap Micro 5.4
From an advisory covering 8 CVEs
 before 4.16.5_08-150400.4.40.1
4.16.5_08-150400.4.40.1
xen
openSUSE:Leap 15.4
From an advisory covering 8 CVEs
 before 4.16.5_08-150400.4.40.1
4.16.5_08-150400.4.40.1
xen
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS
From an advisory covering 2 CVEs
 before 4.13.5_08-150200.3.83.1
4.13.5_08-150200.3.83.1
xen
SUSE:Linux Enterprise Server 15 SP2-LTSS
From an advisory covering 2 CVEs
 before 4.13.5_08-150200.3.83.1
4.13.5_08-150200.3.83.1
xen
SUSE:Linux Enterprise Server for SAP Applications 15 SP2
From an advisory covering 2 CVEs
 before 4.13.5_08-150200.3.83.1
4.13.5_08-150200.3.83.1
xen
SUSE:Linux Enterprise High Performance Computing 15 SP1-LTSS
From an advisory covering 2 CVEs
 before 4.12.4_42-150100.3.98.1
4.12.4_42-150100.3.98.1
xen
SUSE:Linux Enterprise Server 15 SP1-LTSS
From an advisory covering 2 CVEs
 before 4.12.4_42-150100.3.98.1
4.12.4_42-150100.3.98.1
xen
SUSE:Linux Enterprise Server for SAP Applications 15 SP1
From an advisory covering 2 CVEs
 before 4.12.4_42-150100.3.98.1
4.12.4_42-150100.3.98.1
xen
SUSE:Linux Enterprise Software Development Kit 12 SP5
From an advisory covering 2 CVEs
 before 4.12.4_42-3.100.1
4.12.4_42-3.100.1
xen
SUSE:Linux Enterprise Server 12 SP5
From an advisory covering 2 CVEs
 before 4.12.4_42-3.100.1
4.12.4_42-3.100.1
xen
SUSE:Linux Enterprise Server for SAP Applications 12 SP5
From an advisory covering 2 CVEs
 before 4.12.4_42-3.100.1
4.12.4_42-3.100.1
xen
SUSE:Linux Enterprise Micro 5.5
From an advisory covering 2 CVEs
 before 4.17.3_02-150500.3.18.1
4.17.3_02-150500.3.18.1
xen
SUSE:Linux Enterprise Module for Basesystem 15 SP5
From an advisory covering 2 CVEs
 before 4.17.3_02-150500.3.18.1
4.17.3_02-150500.3.18.1
xen
SUSE:Linux Enterprise Module for Server Applications 15 SP5
From an advisory covering 2 CVEs
 before 4.17.3_02-150500.3.18.1
4.17.3_02-150500.3.18.1
xen
openSUSE:Leap 15.5
From an advisory covering 2 CVEs
 before 4.17.3_02-150500.3.18.1
4.17.3_02-150500.3.18.1
xen
Ubuntu:16.04:LTS
 All versions, plus listed versions
4.5.1-0ubuntu14.5.1-0ubuntu24.6.0-1ubuntu14.6.0-1ubuntu24.6.0-1ubuntu4
Show 7 moreShow less
4.6.0-1ubuntu4.14.6.0-1ubuntu4.24.6.0-1ubuntu4.34.6.5-0ubuntu14.6.5-0ubuntu1.14.6.5-0ubuntu1.24.6.5-0ubuntu1.4
 None known
xen
Ubuntu:18.04:LTS
 All versions, plus listed versions
4.9.0-0ubuntu34.9.0-0ubuntu44.9.2-0ubuntu1
 None known
xen
Ubuntu:20.04:LTS
 All versions, plus listed versions
4.9.2-0ubuntu24.9.2-0ubuntu64.9.2-0ubuntu74.11.3+24-g14b62ab3e5-1ubuntu14.11.3+24-g14b62ab3e5-1ubuntu24.11.3+24-g14b62ab3e5-1ubuntu2.24.11.3+24-g14b62ab3e5-1ubuntu2.3
 None known
xen
Ubuntu:22.04:LTS
 All versions, plus listed versions
4.11.4+24-gddaaccbbab-1ubuntu24.16.0-1~ubuntu24.16.0-1~ubuntu2.1
 None known
xen
Ubuntu:24.04:LTS
 All versions, plus listed versions
4.17.2-14.17.2+55-g0b56bed864-14.17.2+76-ge1f9cb16e2-14.17.2+76-ge1f9cb16e2-1ubuntu14.17.3+10-g091466ba55-14.17.3+10-g091466ba55-1.1ubuntu24.17.3+10-g091466ba55-1.1ubuntu3
 None known
xen
Ubuntu:25.10
 All versions, plus listed versions
4.20.0-1ubuntu14.20.0+68-g35cb38b222-1
 None known
xen
Ubuntu:26.10
 All versions, plus listed versions
4.20.2+7-g1badcf5035-2build24.20.2+37-g61ff35323e-1ubuntu14.20.3+127-gc42374a105-1
 None known
xen
Ubuntu:26.04:LTS
 All versions, plus listed versions
4.20.0+68-g35cb38b222-14.20.2+7-g1badcf5035-24.20.2+7-g1badcf5035-2build2
 None known
xen
openSUSE:Tumbleweed
From an advisory covering 6 CVEs
 before 4.18.0_02-1.1
4.18.0_02-1.1

History

History
RecordedChangedSources
affected, facts
first indexedCVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2023-46836 is a medium vulnerability (CVSS 4.7) in Xen, published November 16, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 16th percentile. Fixed in xen 4.15.5-r3.

References

Show 26 moreShow less
Pages All vulnerabilities Browse Docs Sources Guide Get API key
MoveEnter Open