CyberSecBulletin
CVE-2026-68297NVD status: Received

Linux: Integer Overflow or Wraparound

Published Updated By the CyberSecBulletin desk

CVE-2026-68297 is a high-severity integer overflow or wraparound vulnerability in Linux, with a CVSS 3.1 base score of 7.8 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 8bfdfe0dbb36a650b7c4dec1aeae078319938a0b, dc4b577a083b361d25e118dc96d8281255ebe22c, dfdfd987f1917c84766e097a6120a1f3f1634940 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 0.13% 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 8bfdfe0dbb36a650b7c4dec1aeae078319938a0b or dc4b577a083b361d25e118dc96d8281255ebe22c or dfdfd987f1917c84766e097a6120a1f3f1634940 or f02334a9e378f7e07232b26dc3d2ab353339f040, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux901271e0403af638c224987c2a4e55cebade7e91 up to, but not including, 8bfdfe0dbb36a650b7c4dec1aeae078319938a0b; 901271e0403af638c224987c2a4e55cebade7e91 up to, but not including, dc4b577a083b361d25e118dc96d8281255ebe22c; 901271e0403af638c224987c2a4e55cebade7e91 up to, but not including, dfdfd987f1917c84766e097a6120a1f3f1634940; 901271e0403af638c224987c2a4e55cebade7e91 up to, but not including, f02334a9e378f7e07232b26dc3d2ab353339f040; 901271e0403af638c224987c2a4e55cebade7e91 up to, but not including, f4013598b69457dbea350df52e52daea6faef8eb; 901271e0403af638c224987c2a4e55cebade7e91 up to, but not including, 1b8fb5a20508bfb0db854e01214888c761b3a911; 901271e0403af638c224987c2a4e55cebade7e91 up to, but not including, c1cda72f6acec02ebd45d913bf8527ff77336ba6; 901271e0403af638c224987c2a4e55cebade7e91 up to, but not including, 9f29cd8a8e7901a2617c8064ce9f50fc67b97cb8; and 1 more ranges8bfdfe0dbb36a650b7c4dec1aeae078319938a0b, dc4b577a083b361d25e118dc96d8281255ebe22c, dfdfd987f1917c84766e097a6120a1f3f1634940, f02334a9e378f7e07232b26dc3d2ab353339f040, f4013598b69457dbea350df52e52daea6faef8eb, 1b8fb5a20508bfb0db854e01214888c761b3a911

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
HighData or code can be modified at will.
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:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: tipc: fix u16 MTU truncation in media and bearer MTU validation Both TIPC_NL_MEDIA_SET and TIPC_NL_BEARER_SET accept user-supplied MTU values but only enforce a minimum bound, not a maximum. When a user sets the MTU to a value exceeding U16_MAX (65535), it passes validation but is silently truncated when assigned to u16 fields l->mtu and l->advertised_mtu in tipc_link_create(). Values like 65536 (0x10000) truncate to 0, causing a division by zero in tipc_link_set_queue_limits() which computes TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE). Other overflowing values (e.g. 65537-131071) produce small incorrect MTU values, resulting in link malfunction behaviors. Crash stack (triggered as unprivileged user via user namespace): tipc_link_set_queue_limits net/tipc/link.c:2531 tipc_link_create net/tipc/link.c:520 tipc_node_check_dest net/tipc/node.c:1279 tipc_disc_rcv net/tipc/discover.c:252 tipc_rcv net/tipc/node.c:2129 tipc_udp_recv net/tipc/udp_media.c:392 Two independent paths lack the upper bound check: 1. tipc_udp_mtu_bad() -- called from __tipc_nl_media_set() (MEDIA_SET) 2. inline check in __tipc_nl_bearer_set() at bearer.c:1160 (BEARER_SET) Fix both by rejecting MTU values above U16_MAX.

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

The underlying weakness: Integer Overflow or Wraparound

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

How developers prevent this class of flaw

  • Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. If possible, choose a language or compiler that performs automatic bounds checking.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Use libraries or frameworks that make it easier to handle numbers without unexpected consequences. Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++).

More Integer Overflow or Wraparound vulnerabilities (CWE-190)

Timeline

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

References

Recent Integer Overflow or Wraparound vulnerabilities

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