CyberSecBulletin
CVE-2026-45843NVD status: Modified

Linux: Buffer Over-read

Published Updated By the CyberSecBulletin desk

CVE-2026-45843 is a high-severity buffer over-read vulnerability in Linux, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 6268f01ae989013671b526c883e92655342c6f6f, 9aafba2f49e1fcccc2018816f5836a609c925879, 335957df4ed60f02a2ec0432fbedbf0cc7241d8b 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 0.4% 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 6268f01ae989013671b526c883e92655342c6f6f or 9aafba2f49e1fcccc2018816f5836a609c925879 or 335957df4ed60f02a2ec0432fbedbf0cc7241d8b or 37537e42e6df387398bee85cb85070cc80bb1e10, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.258 or 5.15.209 or 6.1.175 or 6.6.141, whichever matches your release line, or a later version.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 6268f01ae989013671b526c883e92655342c6f6f; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 9aafba2f49e1fcccc2018816f5836a609c925879; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 335957df4ed60f02a2ec0432fbedbf0cc7241d8b; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 37537e42e6df387398bee85cb85070cc80bb1e10; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 4cefe32639933d652614b0bd50f818f9af4af78f; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 0511ecb00e61bf28e2fec4bb41fcce385c3a3b2d; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, d42bec6e4f6d6d658be365539400b3314b76b2a7; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 4c1367a2d7aad643a6f87c6931b13cc1a25e8ca7; and 1 more ranges6268f01ae989013671b526c883e92655342c6f6f, 9aafba2f49e1fcccc2018816f5836a609c925879, 335957df4ed60f02a2ec0432fbedbf0cc7241d8b, 37537e42e6df387398bee85cb85070cc80bb1e10, 4cefe32639933d652614b0bd50f818f9af4af78f, 0511ecb00e61bf28e2fec4bb41fcce385c3a3b2d
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystemall versionsNot stated
LinuxLinux Kernel2.6.12.1 up to, but not including, 5.10.258; 5.11 up to, but not including, 5.15.209; 5.16 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.141; 6.7 up to, but not including, 6.12.91; 6.13 up to, but not including, 6.18.33; 6.19 up to, but not including, 7.0.10; 2.6.125.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33

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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
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
LowLimited modification of data is possible.
Availability
NoneAvailability is not affected.

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

Official description

In the Linux kernel, the following vulnerability has been resolved: slip: bound decode() reads against the compressed packet length slhc_uncompress() parses a VJ-compressed TCP header by advancing a pointer through the packet via decode() and pull16(). Neither helper bounds-checks against isize, and decode() masks its return with & 0xffff so it can never return the -1 that callers test for -- those error paths are dead code. A short compressed frame whose change byte requests optional fields lets decode() read past the end of the packet. The over-read bytes are folded into the cached cstate and reflected into subsequent reconstructed packets. Make decode() and pull16() take the packet end pointer and return -1 when exhausted. Add a bounds check before the TCP-checksum read. The existing == -1 tests now do what they were always meant to.

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

The underlying weakness: Buffer Over-read

The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.

More Buffer Over-read vulnerabilities (CWE-126)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Buffer Over-read vulnerabilities

Spotted an error? Tell us.