CVE-2026-46318 — Revert "mm/hugetlbfs: update hugetlbfs to use mmap_prepare"
In the Linux kernel, the following vulnerability has been resolved: Revert "mm/hugetlbfs: update hugetlbfs to use mmap_prepare" This reverts commit ea52cb24cd3f ("mm/hugetlbfs: update hugetlbfs to use mmap_prepare") with conflict resolution to account for changes in commit ea52cb24cd3f ("mm/hugetlbfs: update hugetlbfs to use mmap_prepare"). The patch incorrectly handled hugetlb VMA lock allocation at the mmap_prepare stage, where a failed allocation occurring after mmap_prepare is called might result in the lock leaking. There is no risk of a merge causing a similar issues, as VMA_DONTEXPAND_BIT is set for hugetlb mappings. As a first step in addressing this issue, simply revert the change so we can rework how we do this having corrected the underlying issues. We maintain the VMA flags changes as best we can, accounting for the fact that we were working with a VMA descriptor previously and propagating like-for-like changes for this. Note that we invoke vma_set_flags() and do not call vma_start_write() as vm_flags_set() does. This is OK as it's being done in an .mmap hook where the VMA is not yet linked into the tree so nobody else can be accessing it.
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)
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, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ ea52cb24cd3fb121283754ab82b2cb3044609359 and < 3af5fc3f0ac98c624c109c8c0796fa46e814344c≥ ea52cb24cd3fb121283754ab82b2cb3044609359 and < 83f9efcce93f8574be2279090ee2aec58b86cda7version 6.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 6.19 and < 7.0.12version 7.1-rc1version 7.1-rc2version 7.1-rc3version 7.1-rc4version 7.1-rc5 | 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) EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.14%
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.
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
2 on the record
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-2026-98431 RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency 2d
- Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 2d
- Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 2d
- Unknown CVE-2026-98428 ALSA: usb: 6fire: Avoid embedded URBs 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 CWE classification.
- 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-2026-46318 is "Revert "mm/hugetlbfs: update hugetlbfs to use mmap_prepare"", 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 0.14% 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.
Comments
Moderated technical discussion. Read the community guidelines.
No comments yet.
Sign in or create an account to comment and suggest corrections.