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NVD / CVE Program· CNA Linux

CVE-2026-52958: libceph: Fix potential out-of-bounds access in osdmap_decode()

CriticalCVSS 9.1 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 36/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.73% (FIRST EPSS); higher than 54.8% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Linux Linux 0d2dd7e6bb74fd7712aa73457a4a821906c6863a, 35d0ed82d03e5ee77ea4f31f20e29562a7721649, 36a79759a288961b1ff28a68ec2d1f56f6848098; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.143.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0d2dd7e6bb74fd7712aa73457a4a821906c6863a, 35d0ed82d03e5ee77ea4f31f20e29562a7721649, 36a79759a288961b1ff28a68ec2d1f56f6848098; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.143.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In 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).

Published
Jun 24, 2026
Updated
Oct 19, 2026
EPSS
0.7% · 54th percentile

Report tools

JSON

Action score

36

Monitor

Low priority for now.

CVSS
36 / 40 · 9.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
9.1
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-52958

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.3affected
    • dcbc919a5dc8c2629684a113a90c0b6fe10c3462 and later · before 36a79759a288961b1ff28a68ec2d1f56f6848098affected · git
    • dcbc919a5dc8c2629684a113a90c0b6fe10c3462 and later · before 3f2575bb7f955d42569d96c3e04fa958a0dcf4b4affected · git
    • dcbc919a5dc8c2629684a113a90c0b6fe10c3462 and later · before 8713bbc4b2b9ad78f803978e54b7e49dd21bd9beaffected · git
    • dcbc919a5dc8c2629684a113a90c0b6fe10c3462 and later · before 0d2dd7e6bb74fd7712aa73457a4a821906c6863aaffected · git
    • dcbc919a5dc8c2629684a113a90c0b6fe10c3462 and later · before e7187f33c02488697ec0d01d82bf7a3f8deaba8faffected · git
    • dcbc919a5dc8c2629684a113a90c0b6fe10c3462 and later · before 48df98d12b15360cd56af5c1f460307b340c1197affected · git
    • dcbc919a5dc8c2629684a113a90c0b6fe10c3462 and later · before ee933694645dac062d65fc2743f92bc06fa0db6baffected · git
    • dcbc919a5dc8c2629684a113a90c0b6fe10c3462 and later · before 35d0ed82d03e5ee77ea4f31f20e29562a7721649affected · git
    • before 5.3not affected · semver
Affected versions · NVD (8)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel5.3 and later · before 5.10.258
  • linux linux kernel5.11 and later · before 5.15.209
  • linux linux kernel5.16 and later · before 6.1.175
  • linux linux kernel6.2 and later · before 6.6.141
  • linux linux kernel6.7 and later · before 6.12.91
  • linux linux kernel6.13 and later · before 6.18.33
  • linux linux kernel6.19 and later · before 7.0.10
  • linux linux kernel7.1

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.94-16.12.94-1
Debian:14linuxbefore 7.0.10-17.0.10-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-52956Jun 24, 2026 · libceph: Fix potential out-of-bounds access in __ceph_x_decrypt()
    30Monitor
  • ← EarlierCVE-2026-52957Jun 24, 2026 · libceph: Fix potential null-ptr-deref in decode_choose_args()
    30Monitor
  • Later →CVE-2026-52960Jun 24, 2026 · ceph: put folios not suitable for writeback
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux0d2dd7e6bb74fd7712aa73457a4a821906c6863aVendor (CNA)
Linux Linux35d0ed82d03e5ee77ea4f31f20e29562a7721649Vendor (CNA)
Linux Linux36a79759a288961b1ff28a68ec2d1f56f6848098Vendor (CNA)
Linux Linux3f2575bb7f955d42569d96c3e04fa958a0dcf4b4Vendor (CNA)
Linux Linux48df98d12b15360cd56af5c1f460307b340c1197Vendor (CNA)
Linux Linux8713bbc4b2b9ad78f803978e54b7e49dd21bd9beVendor (CNA)
Linux Linuxe7187f33c02488697ec0d01d82bf7a3f8deaba8fVendor (CNA)
Linux Linuxee933694645dac062d65fc2743f92bc06fa0db6bVendor (CNA)
azl3 kernel 6.6.139.1-1 on Azure Linux 3.06.6.143.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.176-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records