CyberSecBulletin
CVE-2025-39853NVD status: Modified

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2025-39853 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 971feafe157afac443027acdc235badc6838560b, 3c6fb929afa313d9d11f780451d113f73922fe5d, 1eadabcf5623f1237a539b16586b4ed8ac8dffcd as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 971feafe157afac443027acdc235badc6838560b or 3c6fb929afa313d9d11f780451d113f73922fe5d or 1eadabcf5623f1237a539b16586b4ed8ac8dffcd or e2a5e74879f9b494bbd66fa93f355feacde450c7, whichever matches your release line, or a later version.
  2. Update RUGGEDCOM RST2428P to V3.3 or a later version.
  3. Update SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family to V3.3 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxe3219ce6a775468368fb270fae3eb82a6787b436 up to, but not including, 971feafe157afac443027acdc235badc6838560b; e3219ce6a775468368fb270fae3eb82a6787b436 up to, but not including, 3c6fb929afa313d9d11f780451d113f73922fe5d; e3219ce6a775468368fb270fae3eb82a6787b436 up to, but not including, 1eadabcf5623f1237a539b16586b4ed8ac8dffcd; e3219ce6a775468368fb270fae3eb82a6787b436 up to, but not including, e2a5e74879f9b494bbd66fa93f355feacde450c7; e3219ce6a775468368fb270fae3eb82a6787b436 up to, but not including, fb216d980fae6561c7c70af8ef826faf059c6515; e3219ce6a775468368fb270fae3eb82a6787b436 up to, but not including, 66e7cdbda74ee823ec2bf7b830ebd235c54f5ddf; e3219ce6a775468368fb270fae3eb82a6787b436 up to, but not including, 9c21fc4cebd44dd21016c61261a683af390343f8; e3219ce6a775468368fb270fae3eb82a6787b436 up to, but not including, a556f06338e1d5a85af0e32ecb46e365547f92b9; and 1 more ranges971feafe157afac443027acdc235badc6838560b, 3c6fb929afa313d9d11f780451d113f73922fe5d, 1eadabcf5623f1237a539b16586b4ed8ac8dffcd, e2a5e74879f9b494bbd66fa93f355feacde450c7, fb216d980fae6561c7c70af8ef826faf059c6515, 66e7cdbda74ee823ec2bf7b830ebd235c54f5ddf
SiemensRUGGEDCOM RST2428Pbefore V3.3V3.3
SiemensSCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 familybefore V3.3V3.3
SiemensSCALANCE XCH328before V3.3V3.3
SiemensSCALANCE XCM324before V3.3V3.3
SiemensSCALANCE XCM328before V3.3V3.3
SiemensSCALANCE XCM332before V3.3V3.3
SiemensSCALANCE XRH334 (24 V DC, 8xFO, CC)before V3.3V3.3
SiemensSCALANCE XRM334 (230 V AC, 12xFO)before V3.3V3.3
SiemensSCALANCE XRM334 (230 V AC, 8xFO)before V3.3V3.3
SiemensSCALANCE XRM334 (230V AC, 2x10G, 24xSFP, 8xSFP+)before V3.3V3.3
SiemensSCALANCE XRM334 (24 V DC, 12xFO)before V3.3V3.3
SiemensSCALANCE XRM334 (24 V DC, 8xFO)before V3.3V3.3
SiemensSCALANCE XRM334 (24V DC, 2x10G, 24xSFP, 8xSFP+)before V3.3V3.3
SiemensSCALANCE XRM334 (2x230 V AC, 12xFO)before V3.3V3.3
SiemensSCALANCE XRM334 (2x230 V AC, 8xFO)before V3.3V3.3
SiemensSCALANCE XRM334 (2x230V AC, 2x10G, 24xSFP, 8xSFP+)before V3.3V3.3
SiemensSIMATIC CN 4100before V5.0V5.0
LinuxLinux Kernel4.6 up to, but not including, 5.4.299; 5.5 up to, but not including, 5.10.243; 5.11 up to, but not including, 5.15.192; 5.16 up to, but not including, 6.1.151; 6.2 up to, but not including, 6.6.105; 6.7 up to, but not including, 6.12.46; 6.13 up to, but not including, 6.16.6; 6.175.4.299, 5.10.243, 5.15.192, 6.1.151, 6.6.105, 6.12.46
DebianDebian Linux11.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: i40e: Fix potential invalid access when MAC list is empty list_first_entry() never returns NULL - if the list is empty, it still returns a pointer to an invalid object, leading to potential invalid memory access when dereferenced. Fix this by using list_first_entry_or_null instead of list_first_entry.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Recent Out-of-bounds Read vulnerabilities

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