CVE-2026-23309 — tracing: Add NULL pointer check to trigger_data_free()
In the Linux kernel, the following vulnerability has been resolved: tracing: Add NULL pointer check to trigger_data_free() If trigger_data_alloc() fails and returns NULL, event_hist_trigger_parse() jumps to the out_free error path. While kfree() safely handles a NULL pointer, trigger_data_free() does not. This causes a NULL pointer dereference in trigger_data_free() when evaluating data->cmd_ops->set_filter. Fix the problem by adding a NULL pointer check to trigger_data_free(). The problem was found by an experimental code review agent based on gemini-3.1-pro while reviewing backports into v6.18.y.
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 0.1% (30-day exploitation probability)+0
- Technical severity (medium)+3
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.
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)
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 |
≥ 9b0513905e0598b9f8cfccab8e47497aed5d935d and < 42b380f97d65e76e7b310facd525f730272daf57≥ 6.19.4 and < 6.19.7≥ 6.18.14 and < 6.18.17≥ 6.12.75 and < 6.12.77≥ 6.6.128 and < 6.6.130≥ 6.1.165 and < 6.1.167≥ 0550069cc25f513ce1f109c88f7c1f01d63297db and < 457965c13f0837a289c9164b842d0860133f6274≥ e42efbe9754da78eafe11f6bd3ca9c8a094a752a and < 477469223b2b840f436ce204333de87cb17e5d93 and 3 more≥ 335dfe4bc6368e70e8c15419375cf609c4f85558 and < 2ce8ece5a78da67834db7728edc801889a64f643≥ 7e6556e9329bc484e9dcdab6e346d959267c0636 and < 59c15b9cc453b74beb9f04c6c398717e73612dc3≥ c10f0efe57728508d796ae4ba7abe4c14ec3d8ef and < 13dcd9269e225e4c4ceabdaeebe2ce4661b54c6e |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 6.1.165 and < 6.1.167version 7.0-rc2version 7.0-rc1≥ 6.19.4 and < 6.19.7≥ 6.18.14 and < 6.18.17≥ 6.12.75 and < 6.12.77≥ 6.6.128 and < 6.6.130 | 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 |
|---|---|---|---|---|---|
| 5.5 | CVSS 3.1 | Medium | 1.8 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.12%
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
- Record published
- Fix documented
- CVSS changed · 5.5
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
6 on the record
- git.kernel.org/stable/c/13dcd9269e225e4c4ceabdaeebe2ce4661b54c6e
- git.kernel.org/stable/c/59c15b9cc453b74beb9f04c6c398717e73612dc3
- git.kernel.org/stable/c/477469223b2b840f436ce204333de87cb17e5d93
- git.kernel.org/stable/c/457965c13f0837a289c9164b842d0860133f6274
- git.kernel.org/stable/c/2ce8ece5a78da67834db7728edc801889a64f643
- git.kernel.org/stable/c/42b380f97d65e76e7b310facd525f730272daf57
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 10h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 10h
- 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 CISA SSVC assessment.
- 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-2026-23309 is "tracing: Add NULL pointer check to trigger_data_free()", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.12% 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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