CVE-2024-57951 — hrtimers: Handle CPU state correctly on hotplug
In the Linux kernel, the following vulnerability has been resolved: hrtimers: Handle CPU state correctly on hotplug Consider a scenario where a CPU transitions from CPUHP_ONLINE to halfway through a CPU hotunplug down to CPUHP_HRTIMERS_PREPARE, and then back to CPUHP_ONLINE: Since hrtimers_prepare_cpu() does not run, cpu_base.hres_active remains set to 1 throughout. However, during a CPU unplug operation, the tick and the clockevents are shut down at CPUHP_AP_TICK_DYING. On return to the online state, for instance CFS incorrectly assumes that the hrtick is already active, and the chance of the clockevent device to transition to oneshot mode is also lost forever for the CPU, unless it goes back to a lower state than CPUHP_HRTIMERS_PREPARE once. This round-trip reveals another issue; cpu_base.online is not set to 1 after the transition, which appears as a WARN_ON_ONCE in enqueue_hrtimer(). Aside of that, the bulk of the per CPU state is not reset either, which means there are dangling pointers in the worst case. Address this by adding a corresponding startup() callback, which resets the stale per CPU state and sets the online flag. [ tglx: Make the new callback unconditionally available, remove the online modification in the prepare() callback and clear the remaining state in the starting callback instead of the prepare callback ]
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.3% (30-day exploitation probability)+3
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ 54d0d83a53508d687fd4a225f8aa1f18559562d0 and < 95e4f62df23f4df1ce6ef897d44b8e23c260921aversion 6.7≥ 4.19.302 and < 4.20≥ 6.6.7 and < 6.6.74≥ 6.1.68 and < 6.1.127≥ 5.15.143 and < 5.15.177≥ 5.10.204 and < 5.10.234≥ 5.4.264 and < 5.4.290 and 7 moreversion 9a2fc41acb69dd4e2a58d0c04346c3333c2341fc≥ 5c0930ccaad5a74d74e8b18b648c5eb21ed2fe94 and < 2f8dea1692eef2b7ba6a256246ed82c365fdc686≥ 5c0930ccaad5a74d74e8b18b648c5eb21ed2fe94 and < 38492f6ee883c7b1d33338bf531a62cff69b4b28≥ 53f408cad05bb987af860af22f4151e5a18e6ee8 and < a5cbbea145b400e40540c34816d16d36e0374fbc≥ 75b5016ce325f1ef9c63e5398a1064cf8a7a7354 and < 3d41dbf82e10c44e53ea602398ab002baec27e75≥ 6fcbcc6c8e52650749692c7613cbe71bf601670d and < 15b453db41d36184cf0ccc21e7df624014ab6a1a≥ 7f4c89400d2997939f6971c7981cc780a219e36b and < 14984139f1f2768883332965db566ef26db609e7 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
≥ 4.19.302 and < 4.20version 6.13-rc7version 6.13-rc6version 6.13-rc5version 6.13-rc4version 6.13-rc3version 6.13-rc2version 6.13-rc1 and 6 more≥ 6.7 and < 6.12.11≥ 6.6.7 and < 6.6.74≥ 6.1.68 and < 6.1.127≥ 5.15.143 and < 5.15.177≥ 5.10.204 and < 5.10.234≥ 5.4.264 and < 5.4.290 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.8 | CVSS 3.1 | High | — | — | CISA-ADP via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · linux/linux kernel
- CVSS changed · 7.8
- Source status changed · → Modified
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
13 on the record
- git.kernel.org/stable/c/15b453db41d36184cf0ccc21e7df624014ab6a1a
- git.kernel.org/stable/c/2f8dea1692eef2b7ba6a256246ed82c365fdc686
- git.kernel.org/stable/c/3d41dbf82e10c44e53ea602398ab002baec27e75
- git.kernel.org/stable/c/95e4f62df23f4df1ce6ef897d44b8e23c260921a
- git.kernel.org/stable/c/14984139f1f2768883332965db566ef26db609e7
- git.kernel.org/stable/c/a5cbbea145b400e40540c34816d16d36e0374fbc
- git.kernel.org/stable/c/38492f6ee883c7b1d33338bf531a62cff69b4b28
- lists.debian.org/debian-lts-announce/2025/03/msg00001.html
- nvd.nist.gov/vuln/detail/CVE-2024-57951
- cert-portal.siemens.com/productcert/html/ssa-355557.html
- github.com/advisories/GHSA-5j5f-9wh9-hfj9
- lists.debian.org/debian-lts-announce/2025/03/msg00002.html
- cert-portal.siemens.com/productcert/html/ssa-265688.html
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 7h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 7h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2024-57951 is "hrtimers: Handle CPU state correctly on hotplug", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.26% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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