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CVE-2026-80557

Linux

In the Linux kernel, the following vulnerability has been resolved: libceph: fix OOB read in decode_watchers() via missing bounds check ceph_start_decoding() validates that struct_len bytes remain in the buffer after the encoding header, but accepts struct_len=0 as valid: ceph_decode_need(p, end, 0, bad) always passes. When a malicious or compromised OSD sends an obj_list_watch_response_t reply with struct_len=0, ceph_start_decoding() returns success with p == end, leaving zero bytes guaranteed for subsequent reads. The immediately following ceph_decode_32(p) in decode_watchers() has no pre...

CVSS
9.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.08.27
PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 9.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: libceph: fix OOB read in decode_watchers() via missing bounds check ceph_start_decoding() validates that struct_len bytes remain in the buffer after the encoding header, but accepts struct_len=0 as valid: ceph_decode_need(p, end, 0, bad) always passes. When a malicious or compromised OSD sends an obj_list_watch_response_t reply with struct_len=0, ceph_start_decoding() returns success with p == end, leaving zero bytes guaranteed for subsequent reads. The immediately following ceph_decode_32(p) in decode_watchers() has no pre...

Affected product and versions

Product
Linux
Affected versions
>= a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c < 85479b7d65b4ebcb07fbbe57230976793974ab4a, >= a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c < 1c824e7c75bb4adf19553dd4ea944a5d83096be8, >= a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c < f161be39201eb5f9b1f58fb8f90b8a9cd3931eb6, >= a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c < eab3eeb68bfc639d74f27256f05546af5c4f787d, >= a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c < c59219a6b62d74936963983e5815524c3de8dd79, >= a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c < cb8246e5846dbbe34930903a90c7a90dd8e5910b, >= a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c < 7130d94846dadbb97b6b7f4d78a3a7bba6e3daa1, >= a4ed38d7a180f184a6e7aedd09db9ca4b1e6a71c < 00ead17c7de137a692edee59f2772e6af687e8eb, >= 4.9
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
Not available