CyberSecBulletin
CVE-2026-72029NVD status: Received

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2026-72029 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions 155851e501d6c649cbcfcca6472dc26269b04b6b, 2b822df8e498aa6ca828e16afd8ffec27f7e4c88, 55cfea8e8d9117ad086d1e1a0ff87f306f8e3ad0 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 155851e501d6c649cbcfcca6472dc26269b04b6b or 2b822df8e498aa6ca828e16afd8ffec27f7e4c88 or 55cfea8e8d9117ad086d1e1a0ff87f306f8e3ad0 or 07f5eb6d268a37bd9e131079489655cd599182e0, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux1f52d7b622854b8bd7a1be3de095ca2e1f77098e up to, but not including, 155851e501d6c649cbcfcca6472dc26269b04b6b; 1f52d7b622854b8bd7a1be3de095ca2e1f77098e up to, but not including, 2b822df8e498aa6ca828e16afd8ffec27f7e4c88; 1f52d7b622854b8bd7a1be3de095ca2e1f77098e up to, but not including, 55cfea8e8d9117ad086d1e1a0ff87f306f8e3ad0; 1f52d7b622854b8bd7a1be3de095ca2e1f77098e up to, but not including, 07f5eb6d268a37bd9e131079489655cd599182e0; 1f52d7b622854b8bd7a1be3de095ca2e1f77098e up to, but not including, 77f0023f22f6a2616ae128e9c93961b24ae52611; 1f52d7b622854b8bd7a1be3de095ca2e1f77098e up to, but not including, 526b8ef54668780c8f69e0211c342763d5dcbad1; 5.18155851e501d6c649cbcfcca6472dc26269b04b6b, 2b822df8e498aa6ca828e16afd8ffec27f7e4c88, 55cfea8e8d9117ad086d1e1a0ff87f306f8e3ad0, 07f5eb6d268a37bd9e131079489655cd599182e0, 77f0023f22f6a2616ae128e9c93961b24ae52611, 526b8ef54668780c8f69e0211c342763d5dcbad1

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
AdjacentThe attacker must be on the same local network segment.
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
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:A/AC:L/PR:N/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: net: wwan: iosm: bound device offsets in the MUX downlink decoder mux_dl_adb_decode() walks a chain of aggregated datagram tables using offsets and lengths taken from the modem. first_table_index, next_table_index, table_length, datagram_index and datagram_length are all device supplied le values. Only first_table_index was checked, and only for being non zero. The decoder then formed adth = block + adth_index and read the table header and the datagram entries with no bound against the received skb. A modem that reports an index or a length past the downlink buffer makes the decoder read out of bounds. The buffer is IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE and skb->len is at most that, so skb->len is the real limit, but none of these in band offsets were checked against it. The table chain is also followed with no forward progress check. The loop takes the next table from adth->next_table_index and stops only when that reaches zero. A modem can stage two tables that point at each other, so the loop never ends. It runs in softirq and clones the skb on every pass. Validate every device offset and length against skb->len before use. The block header must fit. Each table header, on entry and after every next_table_index, must lie inside the skb. The datagram table must fit. Each datagram index and length must stay inside the skb. The header padding must not exceed the datagram length so the receive length does not wrap. Require each next_table_index to move forward so the chain cannot cycle. This was reproduced under KASAN as a slab out of bounds read on a normal downlink receive once the iosm net device is up.

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: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Read vulnerabilities

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