CVE-2026-64361 — hfs/hfsplus: fix u32 overflow in check_and_correct_requested_length
In the Linux kernel, the following vulnerability has been resolved: hfs/hfsplus: fix u32 overflow in check_and_correct_requested_length check_and_correct_requested_length() compares (off + len) against node_size using u32 arithmetic. When the caller passes a large len value (e.g. from an underflowed subtraction in hfs_brec_remove()), off + len can wrap past 2^32 and produce a small result, causing the bounds check to pass when it should fail. For example, with off=14 and len=0xFFFFFFF2 (underflowed from data_off - keyoffset - size in hfs_brec_remove), off + len wraps to 6, which is less than a typical node_size of 512, so the check passes and the subsequent memmove reads ~4GB past the node buffer. Fix this by widening the addition to u64 before comparing against node_size. This prevents the u32 wrap while keeping the logic straightforward.
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 (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.
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)
- 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 |
≥ a431930c9bac518bf99d6b1da526a7f37ddee8d8 and < 607217f7ad419b53926f71e3f75001813bbc08adversion 6.17≥ 6.16.2 and < 6.17≥ 6.15.11 and < 6.16≥ 5.4.297 and < 5.5≥ 6.12.43 and < 6.12.97≥ 6.6.103 and < 6.6.145≥ 6.1.149 and < 6.1.178 and 12 more≥ 5.15.190 and < 5.15.212≥ 5.10.241 and < 5.10.261version eec522fd0d28106b14a59ab2d658605febe4a3bbversion fc7f732984ec91f30be3e574e0644066d07f2b78version e7d2dc2421e821e4045775e6dc226378328de6f6≥ a431930c9bac518bf99d6b1da526a7f37ddee8d8 and < 966cb76fb2857a4242cab6ea2ea17acf818a3da7≥ a431930c9bac518bf99d6b1da526a7f37ddee8d8 and < c25d3c931a63e762fcaa9cb125b901c53b62403f≥ efc095b35b23297e419c2ab4fc1ed1a8f0781a29 and < 7399c3baee7bb622a92f0b895cd4d3009a693f2b≥ 384a66b89f9540a9a8cb0f48807697dfabaece4c and < b6a481642ea1977be2f84dc08c5affd742c177e7≥ fe2891a9c43ab87d1a210d61e6438ca6936e2f62 and < 671c3fcc2ad31c1311ea6414382a2d95104ae1b9≥ a1a60e79502279f996e55052f50cc14919020475 and < fc9d1447ca3cdc78d2e4ace1ce1f3a7c77ca08b1≥ 67ecc81f6492275c9c54280532f558483c99c90e and < c8dd112173c02adf539fe2ad34a45f5e0068780d |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
≥ 5.4.297 and < 5.5≥ 6.19 and < 7.1.4≥ 6.16.2 and < 6.18.40≥ 6.15.11 and < 6.16≥ 6.12.43 and < 6.12.97≥ 6.6.103 and < 6.6.145≥ 6.1.149 and < 6.1.178≥ 5.15.190 and < 5.15.212 and 1 more≥ 5.10.241 and < 5.10.261 |
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 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 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: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) 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
- Record published
- Fix documented
- CVSS changed · 7.8
- 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 15, 2026 – Oct 15, 2026
References
8 on the record
- git.kernel.org/stable/c/b6a481642ea1977be2f84dc08c5affd742c177e7
- git.kernel.org/stable/c/671c3fcc2ad31c1311ea6414382a2d95104ae1b9
- git.kernel.org/stable/c/966cb76fb2857a4242cab6ea2ea17acf818a3da7
- git.kernel.org/stable/c/c25d3c931a63e762fcaa9cb125b901c53b62403f
- git.kernel.org/stable/c/fc9d1447ca3cdc78d2e4ace1ce1f3a7c77ca08b1
- git.kernel.org/stable/c/7399c3baee7bb622a92f0b895cd4d3009a693f2b
- git.kernel.org/stable/c/c8dd112173c02adf539fe2ad34a45f5e0068780d
- git.kernel.org/stable/c/607217f7ad419b53926f71e3f75001813bbc08ad
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 1d
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 1d
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 2d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 2d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 2d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 2d
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-2026-64361 is "hfs/hfsplus: fix u32 overflow in check_and_correct_requested_length", 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 0.13% 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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