CVE-2024-56595

Local privilege escalation via negative JFS index

Published Dec 27, 2024 · Updated May 11, 2026

Improper array-index validation in affected Linux branches allows local users to escalate privileges through the JFS block-allocation path. In dbAdjTree in fs/jfs/jfs_dmap.c, a loop continues when lp is zero, decrements it below zero, and uses the negative value as an array index. Reachability requires low-privileged local access and execution of the affected JFS path; the write can expose or corrupt kernel memory or interrupt the system.

CVSS severity7.8
High
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper array-index validation in affected Linux branches allows local users to escalate privileges through the JFS block-allocation path. In dbAdjTree in fs/jfs/jfs_dmap.c, a loop continues when lp is zero, decrements it below zero, and uses the negative value as an array index. Reachability requires low-privileged local access and execution of the affected JFS path; the write can expose or corrupt kernel memory or interrupt the system.

The record

CVE
CVE-2024-56595
Published
Dec 27, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-129, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 27, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <368a533152220b0a6f1142327d96c6b6361f3002
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3b5d21b56c3774bc84eab0a93aaac22a4475e2c4
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <491487eeddccc4bb49f2e59d8c8f35bec89c15ca
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8a4311bbde702362fe7412045d06ab6767235dac
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a174706ba4dad895c40b1d2277bade16dfacdcd9
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a3d408870bc19b794646871bc4c3a5daa66f91c5
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b15000bcbecf27e0f7c0f149a409e5b865e28ca2
  8. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <368a533152220b0a6f1142327d96c6b6361f3002; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3b5d21b56c3774bc84eab0a93aaac22a4475e2c4; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <491487eeddccc4bb49f2e59d8c8f35bec89c15ca; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8a4311bbde702362fe7412045d06ab6767235dac; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a174706ba4dad895c40b1d2277bade16dfacdcd9; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a3d408870bc19b794646871bc4c3a5daa66f91c5; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b15000bcbecf27e0f7c0f149a409e5b865e28ca2; version=2.6.12

Published CVSS scores

7.8CISACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.1OracleCVSS: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-129Improper Validation of Array Index
T1068Exploitation for Privilege Escalation

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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