Linux KernelOperating system · Linux
CVE-2026-52958
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: libceph: Fix potential out-of-bounds access in osdmap_decode() When decoding osd_state and osd_weight from an incoming osdmap in osdmap_decode(), both are decoded for each osd, i.e., map->max_osd times. The ceph_decode_need() check only accounts for sizeof(*map->osd_weight) once. This can potentially result in an out-of-bounds memory access if the incoming message is corrupted such that the max_osd value exceeds the actual content of the osdmap message. This patch fixes the issue by changing the corresponding part in the ceph_decode_need() check to account for map->max_osd*sizeof(*map->osd_weight).
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 analysis · high confidenceA bounds check vulnerability exists in the Linux kernel's libceph osdmap_decode() function where ceph_decode_need() only validates buffer size for a single osd_weight entry, but the loop decodes map->max_osd entries. A malicious or corrupted Ceph message with a max_osd value exceeding the actual message content triggers an out-of-bounds memory write.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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
Linux KernelOperating system
>= 5.3, < 5.10.258>= 5.11, < 5.15.209>= 5.16, < 6.1.175>= 6.2, < 6.6.141>= 6.7, < 6.12.91>= 6.13, < 6.18.33>= 6.19, < 7.0.10= 7.1CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check kernel version against affected rangesRun `uname -r` or `cat /proc/version` to get the kernel version, then compare it to the affected ranges: >= 5.3, < 5.10.258; >= 5.11, < 5.15.209; >= 5.16, < 6.1.175; >= 6.2, < 6.6.141; >= 6.7, < 6.12.91; >= 6.13, < 6.18.33; >= 6.19, < 7.0.10; = 7.1Affected if Kernel version falls within any of the listed affected ranges AND the system uses libceph functionality
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Determine if libceph module is loadedRun `lsmod | grep ceph` or check /proc/modules for the ceph moduleAffected if The ceph or libceph module is loaded in memory
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Check for active Ceph configuration or daemonsLook for Ceph configuration files in /etc/ceph/, or check for ceph-related processes via `ps aux | grep -E 'ceph|osd|mon|mgr'`, or check for ceph kernel module presence in /sys/module/Affected if Ceph configuration files exist or Ceph daemons (osd, mon, mgr) are running on the system
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Verify if the system participates in Ceph cluster network trafficReview network configuration for Ceph cluster traffic (typically port 6789/3300 for mon, 6800-7300 for OSD), check firewall rules or network logs for ceph-related trafficAffected if The system receives OSD map messages from untrusted networks, as the attack vector requires processing crafted Ceph network messages
A system is affected if it runs a vulnerable kernel version from the listed ranges AND uses libceph to process OSD map messages from the network.
Generated from the published advisory. Verify against your own configuration.
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 · scoped5.10.2585.15.2096.1.175
Apply the kernel patch that corrects the ceph_decode_need() check to multiply max_osd by sizeof(*map->osd_weight), then rebuild the kernel or ceph module and restart affected Ceph services.
Upgrade to kernel 5.10.258, 5.15.209, 6.1.175, or 6.6.141 (or later) depending on your current branch
- Identify the currently running Linux kernel version using 'uname -r'
- Check if the running version is within any of the affected ranges: 5.3 to 5.10.257, 5.11 to 5.15.208, 5.16 to 6.1.174, or 6.2 to 6.6.140
- If affected, plan for a kernel upgrade to the appropriate fixed version for your branch: 5.10.258+, 5.15.209+, 6.1.175+, or 6.6.141+
- For production systems, test the new kernel in a staging environment before deploying
- Schedule a maintenance window for the kernel upgrade
- Upgrade the kernel package using your distribution's package manager (e.g., apt-get update && apt-get install linux-image-<version>, yum update kernel, or dnf upgrade kernel)
- Reboot the system to load the new kernel
- Verify the new kernel version is running with 'uname -r'
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Linux Kernel
Scoped from the published advisory
- Consultation1.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,904.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-52958 — 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-2026-52958 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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