CVE-2025-38067 | rseq: Fix segfault on registration when rseq_cs is non-zero

In the Linux kernel, the following vulnerability has been resolved: rseq: Fix segfault on registration when rseq_cs is non-zero The rseq_cs field is documented as being set to 0 by user-space prior to registration, however this is not currently enforced by the kernel. This can result in a segfault on return to user-space if the value stored in the rseq_cs field doesn't point to a valid struct rseq_cs. The correct solution to this would be to fail the rseq registration when the rseq_cs field is non-zero. However, some older versions of glibc will reuse the rseq area of previous threads without clearing the rseq_cs field and will also terminate the process if the rseq registration fails in a secondary thread. This wasn't caught in testing because in this case the leftover rseq_cs does point to a valid struct rseq_cs. What we can do is clear the rseq_cs field on registration when it's non-zero which will prevent segfaults on registration and won't break the glibc versions that reuse rseq areas on thread creation.

Published: 2025-06-18 Last update: 2026-06-17 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-38067 is rated Low Risk (35.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.47%). 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-2025-38067

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 0.12% 0.47% +0.35%
2 2026-04-14 0.03% 0.12% +0.09%
3 2025-12-18 — 0.03% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38067

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-2025-38067

GitHub Security Advisory for CVE-2025-38067

GHSA-627j-hqc4-995q · Severity: medium — In the Linux kernel, the following vulnerability has been resolved: rseq: Fix segfault on...

OS Trackers for CVE-2025-38067

vendor priority summary link
debian not yet assigned CVE-2025-38067 not yet assigned 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-2025-38067
redhat medium — https://access.redhat.com/security/cve/CVE-2025-38067
suse medium CVE-2025-38067 severity moderate: SUSE including 25 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 134 product×package rows across 28 product lines (SUSE Linux Enterprise High Availability Extension 15 SP7, SUSE Linux Enterprise Live Patching 12 SP5, … (28 product lines)): Will Not Fix 78, Known Not Affected 56. https://www.suse.com/security/cve/CVE-2025-38067/
ubuntu medium CVE-2025-38067 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, released 169, ignored 168, needed 45, not-affected 21, needs-triage 2, pending 1. https://ubuntu.com/security/CVE-2025-38067

Affected software / configurations for CVE-2025-38067

Vendor Product Version Raw CPE
linux linux_kernel >= 4.18, < 5.10.240 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.11, < 5.15.189 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.16, < 6.1.146 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.99 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.39 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.14.9 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References for CVE-2025-38067

URL Tags
https://git.kernel.org/stable/c/2df285dab00fa03a3ef939b6cb0d0d0aeb0791db Patch
https://git.kernel.org/stable/c/3e4028ef31b69286c9d4878cee0330235f53f218 Patch
https://git.kernel.org/stable/c/48900d839a3454050fd5822e34be8d54c4ec9b86 Patch
https://git.kernel.org/stable/c/b2b05d0dc2f4f0646922068af435aed5763d16ba Patch
https://git.kernel.org/stable/c/eaf112069a904b6207b4106ff083e0208232a2eb Patch
https://git.kernel.org/stable/c/f004f58d18a2d3dc761cf973ad27b4a5997bd876 Patch
https://git.kernel.org/stable/c/fd881d0a085fc54354414aed990ccf05f282ba53 Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-082556.html
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