CVE-2025-37929 | arm64: errata: Add missing sentinels to Spectre-BHB MIDR arrays

In the Linux kernel, the following vulnerability has been resolved: arm64: errata: Add missing sentinels to Spectre-BHB MIDR arrays Commit a5951389e58d ("arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists") added some additional CPUs to the Spectre-BHB workaround, including some new arrays for designs that require new 'k' values for the workaround to be effective. Unfortunately, the new arrays omitted the sentinel entry and so is_midr_in_range_list() will walk off the end when it doesn't find a match. With UBSAN enabled, this leads to a crash during boot when is_midr_in_range_list() is inlined (which was more common prior to c8c2647e69be ("arm64: Make  _midr_in_range_list() an exported function")): | Internal error: aarch64 BRK: 00000000f2000001 [#1] PREEMPT SMP | pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : spectre_bhb_loop_affected+0x28/0x30 | lr : is_spectre_bhb_affected+0x170/0x190 | [...] | Call trace: | spectre_bhb_loop_affected+0x28/0x30 | update_cpu_capabilities+0xc0/0x184 | init_cpu_features+0x188/0x1a4 | cpuinfo_store_boot_cpu+0x4c/0x60 | smp_prepare_boot_cpu+0x38/0x54 | start_kernel+0x8c/0x478 | __primary_switched+0xc8/0xd4 | Code: 6b09011f 54000061 52801080 d65f03c0 (d4200020) | ---[ end trace 0000000000000000 ]--- | Kernel panic - not syncing: aarch64 BRK: Fatal exception Add the missing sentinel entries.

Published: 2025-05-20 Last update: 2025-11-10 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2025-37929 is rated Low Risk (24/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.16%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-37929

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.11% 0.16% +0.05%
2 2026-03-16 0.03% 0.11% +0.08%
3 2025-11-11 0.03%

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-37929

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 3.6 [email protected]

Weakness enumeration for CVE-2025-37929

OS Trackers for CVE-2025-37929

vendor priority summary link
debian unimportant CVE-2025-37929 unimportant priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2025-37929
redhat https://access.redhat.com/security/cve/CVE-2025-37929
suse medium https://www.suse.com/security/cve/CVE-2025-37929/
ubuntu medium CVE-2025-37929 medium priority: Ubuntu including 144 source packages (linux, linux-allwinner-5.19, …), 1289 status rows across 9 suites (bionic, focal, jammy, noble, oracular, plucky, trusty, upstream, xenial): DNE 925, ignored 146, not-affected 126, released 92. https://ubuntu.com/security/CVE-2025-37929

Affected software / configurations for CVE-2025-37929

Vendor Product Version Raw CPE
linux linux_kernel >= 6.1.135, < 6.1.138 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.6.88, < 6.6.90 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.12.24, < 6.12.28 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13.12, < 6.14 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.14.3, < 6.14.6 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 5.15.181 cpe:2.3:o:linux:linux_kernel:5.15.181:*:*:*:*:*:*:*
linux linux_kernel 6.15 cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*
linux linux_kernel 6.15 cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:*
linux linux_kernel 6.15 cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:*
linux linux_kernel 6.15 cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References for CVE-2025-37929

cvelogic Threat Intelligence