CVE Intelligence
High Memory corruption

CVE-2024-40909 — bpf: Fix a potential use-after-free in bpf_link_free()

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix a potential use-after-free in bpf_link_free() After commit 1a80dbcb2dba, bpf_link can be freed by link->ops->dealloc_deferred, but the code still tests and uses link->ops->dealloc afterward, which leads to a use-after-free as reported by syzbot. Actually, one of them should be sufficient, so just call one of them instead of both. Also add a WARN_ON() in case of any problematic implementation.

Published Jul 12, 2024 · Updated Oct 30, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
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.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.28%
ahead of 20% of scored CVEs · Oct 30, 2026
Affects
Linux
Linux and 1 more
CVSS base
7.8
High · 4 source(s)

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.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

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)

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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
  2. Apply the fixed version or the patch documented under Remediation.
  3. 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.

VendorProductVersionsStatusSource
Linux Linux ≥ ac48dc6ac9240f73bf08d29edf65c2deca93ee5d and < e8ccda39b395169622855607085cdeef4d376e0f≥ 876941f533e7b47fc69977fc4551c02f2d18af97 and < 91cff53136daeff50816b0baeafd38a6976f6209≥ 1a80dbcb2dbaf6e4c216e62e30fa7d3daa8001ce and < fa97b8fed9896f1e89cb657513e483a152d4c382≥ 1a80dbcb2dbaf6e4c216e62e30fa7d3daa8001ce and < 2884dc7d08d98a89d8d65121524bb7533183a63aversion 5d8d447777564b35f67000e7838e7ccb64d525c8≥ 6.6.26 and < 6.6.35≥ 6.8.5 and < 6.9version 6.9 Vulnerable CVE Program (cve.org) e CISA ADP
Linux Linux Kernel ≥ 6.6.26 and < 6.6.35≥ 6.9 and < 6.9.6version 6.10-rc1version 6.10-rc2 Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
7.8 CVSS 3.1 High 1.8 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
7.8 CVSS 3.1 High 1.8 5.9 nvd@nist.gov via NIST National Vulnerability Database
7.8 CVSS 3.1 High — — GitHub, Inc. via GitHub Security Advisories
7.8 CVSS 3.1 High — — Linux 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.

CWE-416 · Use After Free

Other CVEs with this weakness →

EPSS over time FIRST

Oct 29, 2026 → Oct 30, 2026 · 2 reading(s) · max 0.28%

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.
endpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · linux/linux
    Oct 30, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 30, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 30, 2026
  • Fix documented
    Oct 30, 2026 · NIST National Vulnerability Database
  • Affected products added · linux/linux kernel
    Oct 30, 2026 · NIST National Vulnerability Database
  • CVSS changed · 7.8
    Oct 30, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 30, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 30, 2026 · Alertas do Telegram
  • 2024
  • CVE published
    Jul 12, 2024 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 30, 2026 – Oct 30, 2026
  • 1× Official description updated · Oct 30, 2026 – Oct 30, 2026

References

6 on the record

Elsewhere on this site

Linux
every CVE for this vendor
Memory corruption
same class
CWE-416
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 3d
  • CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 3d
  • CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 3d
  • CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 3d
  • CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 3d
  • CVE-2026-99210 accel/rocket: clear rdev on device init failure 3d

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-2024-40909 is "bpf: Fix a potential use-after-free in bpf_link_free()", 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 0.28% 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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