CVE-2026-80558Network attack vector

Kernel memory disclosure via unchecked primary_temp index

Published Aug 26, 2026 · Updated Aug 27, 2026

Out-of-bounds read in Linux kernel libceph allows remote attackers to disclose kernel memory or crash a Ceph client via a corrupt OSD map. The get_temp_osds() path accepts an unchecked primary_temp OSD index, which calc_target() uses to read beyond osd_addr, osd_state, and osd_weight. Exploitation requires an already-connected kernel CephFS or RBD client and a compromised or malicious Ceph monitor or OSD; impact is confined to kernel memory disclosure, misrouted connections, and a client-host oops or panic.

CVSS severity9.8
Critical
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux kernel libceph allows remote attackers to disclose kernel memory or crash a Ceph client via a corrupt OSD map. The get_temp_osds() path accepts an unchecked primary_temp OSD index, which calc_target() uses to read beyond osd_addr, osd_state, and osd_weight. Exploitation requires an already-connected kernel CephFS or RBD client and a compromised or malicious Ceph monitor or OSD; impact is confined to kernel memory disclosure, misrouted connections, and a client-host oops or panic.

The record

CVE
CVE-2026-80558
Published
Aug 26, 2026
Updated
Aug 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.15
  2. Affected versionversion=5e8d4d36bf23bb7baf027c479d54395840219928 <1c705fe8e59c6b16f48964973fb23c8ec4735b73
  3. Affected versionversion=5e8d4d36bf23bb7baf027c479d54395840219928 <3660b98d1204b419f6a77e9a295f148dcf38d042
  4. Affected versionversion=5e8d4d36bf23bb7baf027c479d54395840219928 <4f392fec075562dc93bb0c69f37423ca2af9b48f
  5. Affected versionversion=5e8d4d36bf23bb7baf027c479d54395840219928 <505fc50b8ff8e687b7e3ef6866269dea27366224
  6. Affected versionversion=5e8d4d36bf23bb7baf027c479d54395840219928 <6799d4a916ffcb3d450d8440f9fe0f0862f768d6
  7. Affected versionversion=5e8d4d36bf23bb7baf027c479d54395840219928 <dfe1877d351b99eb1b1a62a3fc2d174220e88e20
  8. Affected versionversion=5e8d4d36bf23bb7baf027c479d54395840219928 <e009c5f0ad634c62f5c48a41f1f3c019ecf52555
  9. Affected versionversion=5e8d4d36bf23bb7baf027c479d54395840219928 <e2ffeec85201b2bb748e99e12539ee1b92f62796

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.15; version=5e8d4d36bf23bb7baf027c479d54395840219928 <1c705fe8e59c6b16f48964973fb23c8ec4735b73; version=5e8d4d36bf23bb7baf027c479d54395840219928 <3660b98d1204b419f6a77e9a295f148dcf38d042; version=5e8d4d36bf23bb7baf027c479d54395840219928 <4f392fec075562dc93bb0c69f37423ca2af9b48f; version=5e8d4d36bf23bb7baf027c479d54395840219928 <505fc50b8ff8e687b7e3ef6866269dea27366224; version=5e8d4d36bf23bb7baf027c479d54395840219928 <6799d4a916ffcb3d450d8440f9fe0f0862f768d6; version=5e8d4d36bf23bb7baf027c479d54395840219928 <dfe1877d351b99eb1b1a62a3fc2d174220e88e20; version=5e8d4d36bf23bb7baf027c479d54395840219928 <e009c5f0ad634c62f5c48a41f1f3c019ecf52555; version=5e8d4d36bf23bb7baf027c479d54395840219928 <e2ffeec85201b2bb748e99e12539ee1b92f62796

Published CVSS scores

9.8LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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