In the Linux kernel, the following vulnerability has been resolved: tracing: Add recursion protection in kernel stack trace recording A bug was reported about an infinite recursion caused by tracing the rcu events with the kernel stack trace trigger enabled. The stack trace code called back into RCU which then called the stack trace again. Expand the ftrace recursion protection to add a set of bits to protect events from recursion. Each bit represents the context that the event is in (normal, softirq, interrupt and NMI). Have the stack trace code use the interrupt context to protect against recursion. Note, the bug showed an issue in both the RCU code as well as the tracing stacktrace code. This only handles the tracing stack trace side of the bug. The RCU fix will be handled separately.
Conclusion & alert: CVE-2026-23138 is rated Low Risk (22.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.12%). 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.
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 | 0.02% | 0.12% | +0.10% |
| 2 | 2026-02-15 | — | 0.02% | — |
Full EPSS history (2 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.5 | 3.1 | MEDIUM |
|
1.8 | 3.6 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2026-23138 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. | https://security-tracker.debian.org/tracker/CVE-2026-23138 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2026-23138 |
suse
|
medium | CVE-2026-23138 severity moderate: SUSE including 16 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 65 product×package rows across 13 product lines (SUSE Linux Enterprise Live Patching 12 SP5, SUSE Linux Enterprise Micro 5.0, … (13 product lines)): Known Not Affected 65. | https://www.suse.com/security/cve/CVE-2026-23138/ |
ubuntu
|
medium | CVE-2026-23138 medium priority: Ubuntu including 157 source packages (linux, linux-allwinner-5.19, …), 1256 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): DNE 871, ignored 169, needed 87, released 83, not-affected 46. | https://ubuntu.com/security/CVE-2026-23138 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| linux | linux_kernel | >= 5.8, < 6.18.6 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | 6.19 | cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* |
| linux | linux_kernel | 6.19 | cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* |
| linux | linux_kernel | 6.19 | cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* |
| linux | linux_kernel | 6.19 | cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* |