CVE-2023-52603

Kernel memory corruption via negative JFS index

Published Mar 6, 2024 · Updated Aug 5, 2026

Out-of-bounds access in the Linux JFS directory-tree code allows local users to corrupt kernel memory through a crafted filesystem image. When dtSplitRoot walks a corrupted root-node freelist, an fsi value below -1 indexes rp->slot outside the 128-entry array and later writes through that invalid slot. Exploitation requires a locally mounted, attacker-controlled JFS image and a directory insertion; the resulting access can disclose or corrupt kernel memory or crash the host.

CVSS severity7.8
High
EPSS probability0.29%
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 access in the Linux JFS directory-tree code allows local users to corrupt kernel memory through a crafted filesystem image. When dtSplitRoot walks a corrupted root-node freelist, an fsi value below -1 indexes rp->slot outside the 128-entry array and later writes through that invalid slot. Exploitation requires a locally mounted, attacker-controlled JFS image and a directory insertion; the resulting access can disclose or corrupt kernel memory or crash the host.

The record

CVE
CVE-2023-52603
Published
Mar 6, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-129, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 6, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <27e56f59bab5ddafbcfe69ad7a4a6ea1279c1b16
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6e2902ecc77e9760a9fc447f56d598383e2372d2
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7aa33854477d9c346f5560a1a1fcb3fe7783e2a8
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e30b52a2ea3d1e0aaee68096957cf90a2f4ec5af
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e4cbc857d75d4e22a1f75446e7480b1f305d8d60
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e4ce01c25ccbea02a09a5291c21749b1fc358e39
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <edff092a59260bf0b0a2eba219cb3da6372c2f9f
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fd3486a893778770557649fe28afa5e463d4ed07
  9. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <27e56f59bab5ddafbcfe69ad7a4a6ea1279c1b16; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6e2902ecc77e9760a9fc447f56d598383e2372d2; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7aa33854477d9c346f5560a1a1fcb3fe7783e2a8; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e30b52a2ea3d1e0aaee68096957cf90a2f4ec5af; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e4cbc857d75d4e22a1f75446e7480b1f305d8d60; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e4ce01c25ccbea02a09a5291c21749b1fc358e39; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <edff092a59260bf0b0a2eba219cb3da6372c2f9f; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fd3486a893778770557649fe28afa5e463d4ed07; version=2.6.12

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8NIST NVDCVSS:3.1/AV:L/AC:L/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 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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