CVE-2026-46020
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn the Linux kernel, the following vulnerability has been resolved: mm/damon/core: validate damos_quota_goal->nid for node_mem_{used,free}_bp Patch series "mm/damon/core: validate damos_quota_goal->nid". node_mem[cg]_{used,free}_bp DAMOS quota goals receive the node id. The node id is used for si_meminfo_node() and NODE_DATA() without proper validation. As a result, privileged users can trigger an out of bounds memory access using DAMON_SYSFS. Fix the issues. The issue was originally reported [1] with a fix by another author. The original author announced [2] that they will stop working including the fix that was still in the review stage. Hence I'm restarting this. This patch (of 2): Users can set damos_quota_goal->nid with arbitrary value for node_mem_{used,free}_bp. But DAMON core is using those for si_meminfo_node() without the validation of the value. This can result in out of bounds memory access. The issue can actually triggered using DAMON user-space tool (damo), like below. $ sudo ./damo start --damos_action stat \ --damos_quota_goal node_mem_used_bp 50% -1 \ --damos_quota_interval 1s $ sudo dmesg [...] [ 65.565986] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000098 Fix this issue by adding the validation of the given node. If an invalid node id is given, it returns 0% for used memory ratio, and 100% for free memory ratio.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisThe code reads past the end (or before the start) of a buffer, returning memory that was never meant to be exposed. Attackers use it to leak secrets like keys or to defeat memory-protection defences. Remediation is validating indices and lengths before every read.
General guidance for the out-of-bounds read class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 6.16, < 6.18.27>= 6.19, < 7.0.4CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped6.18.277.0.4
Linux Kernel 6.18.27+ or 7.0.4+ (or latest stable release)
- 1. Identify the current running Linux kernel version using `uname -r`
- 2. Check if the current version is affected: version >= 6.16 and < 6.18.27, OR version >= 6.19 and < 7.0.4
- 3. If affected, plan for a kernel upgrade to a fixed release
- 4. Obtain the patched kernel from your Linux distribution's stable repository or kernel.org
- 5. Apply the upgrade following your distribution's standard kernel update procedure (e.g., `apt upgrade`, `yum update`, or compiling from source)
- 6. Reboot the system into the new kernel
- 7. Verify the running kernel is now >= 6.18.27 or >= 7.0.4 using `uname -r`
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-46020 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-46020 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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