CVE Intelligence
High

CVE-2026-72029 — net: wwan: iosm: bound device offsets in the MUX downlink decoder

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.

Published Aug 15, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
—
No EPSS score.
Affects
Linux
Linux
CVSS base
8.8
High · 2 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux ≥ 1f52d7b622854b8bd7a1be3de095ca2e1f77098e and < 155851e501d6c649cbcfcca6472dc26269b04b6b≥ 1f52d7b622854b8bd7a1be3de095ca2e1f77098e and < 2b822df8e498aa6ca828e16afd8ffec27f7e4c88≥ 1f52d7b622854b8bd7a1be3de095ca2e1f77098e and < 55cfea8e8d9117ad086d1e1a0ff87f306f8e3ad0≥ 1f52d7b622854b8bd7a1be3de095ca2e1f77098e and < 07f5eb6d268a37bd9e131079489655cd599182e0≥ 1f52d7b622854b8bd7a1be3de095ca2e1f77098e and < 77f0023f22f6a2616ae128e9c93961b24ae52611≥ 1f52d7b622854b8bd7a1be3de095ca2e1f77098e and < 526b8ef54668780c8f69e0211c342763d5dcbad1version 5.18 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
8.8 CVSS 3.1 High 2.8 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
8.8 CVSS 3.1 High — — Linux via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Not enough vector or weakness data: use the affected application’s logs as a starting point.
application logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · linux/linux
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 8.8
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Received
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Aug 15, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

6 on the record

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

  • CVE-2026-99999 ipv4: validate checksum_start before completing checksum 11h
  • CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 11h
  • CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
  • CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
  • CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
  • CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No FIRST EPSS score.
  • No fixed version, patch or mitigation documented.
  • No CISA SSVC assessment.
  • No CWE classification.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-72029 is "net: wwan: iosm: bound device offsets in the MUX downlink decoder", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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