CVE-2024-56627

Memory disclosure via unchecked negative SMB offset

Published Dec 27, 2024 · Updated Aug 5, 2026

Out-of-bounds read in affected Linux ksmbd versions allows attackers to read memory before stream_buf via a negative SMB stream offset. ksmbd_vfs_stream_read uses the client-controlled signed offset to index stream_buf without first rejecting negative values, so memcpy reads before the allocated stream data. The path is reachable only when a share enables vfs objects = streams_xattr and the attacker can issue SMB reads against that share.

CVSS severity7.1
High
EPSS probability0.63%
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 affected Linux ksmbd versions allows attackers to read memory before stream_buf via a negative SMB stream offset. ksmbd_vfs_stream_read uses the client-controlled signed offset to index stream_buf without first rejecting negative values, so memcpy reads before the allocated stream data. The path is reachable only when a share enables vfs objects = streams_xattr and the attacker can issue SMB reads against that share.

The record

CVE
CVE-2024-56627
Published
Dec 27, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125, T1210
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 27, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=0626e6641f6b467447c81dd7678a69c66f7746cf <27de4295522e9a33e4a3fc72f7b8193df9eebe41
  2. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <6bd1bf0e8c42f10a9a9679a4c103a9032d30594d
  3. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <81eed631935f2c52cdaf6691c6d48e0b06e8ad73
  4. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <de4d790dcf53be41736239d7ee63849a16ff5d10
  5. Affected versionversion=0626e6641f6b467447c81dd7678a69c66f7746cf <fc342cf86e2dc4d2edb0fc2ff5e28b6c7845adb9
  6. Affected versionversion=5.15

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0626e6641f6b467447c81dd7678a69c66f7746cf <27de4295522e9a33e4a3fc72f7b8193df9eebe41; version=0626e6641f6b467447c81dd7678a69c66f7746cf <6bd1bf0e8c42f10a9a9679a4c103a9032d30594d; version=0626e6641f6b467447c81dd7678a69c66f7746cf <81eed631935f2c52cdaf6691c6d48e0b06e8ad73; version=0626e6641f6b467447c81dd7678a69c66f7746cf <de4d790dcf53be41736239d7ee63849a16ff5d10; version=0626e6641f6b467447c81dd7678a69c66f7746cf <fc342cf86e2dc4d2edb0fc2ff5e28b6c7845adb9; version=5.15

Published CVSS scores

7.1CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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