# CVE-2026-23172: net: wwan: t7xx: fix potential skb->frags overflow in RX path

> A buffer overflow in the Linux kernel t7xx WWAN driver allows malicious firmware to corrupt memory, causing crashes or potential code execution.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Feb 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-23172, DEBIAN-CVE-2026-23172, GHSA-m5mw-gf4c-pwc3, ROOT-OS-UBUNTU-2404-CVE-2026-23172, UBUNTU-CVE-2026-23172

## What is CVE-2026-23172?

CVE-2026-23172 is a high-severity memory corruption vulnerability in Linux kernel, published on 14 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

net: wwan: t7xx: fix potential skb->frags overflow in RX path

When receiving data in the DPMAIF RX path,
the t7xx_dpmaif_set_frag_to_skb() function adds
page fragments to an skb without checking if the number of
fragments has exceeded MAX_SKB_FRAGS. This could lead to a buffer overflow
in skb_shinfo(skb)->frags[] array, corrupting adjacent memory and
potentially causing kernel crashes or other undefined behavior.

This issue was identified through static code analysis by comparing with a
similar vulnerability fixed in the mt76 driver commit b102f0c522cf ("mt76:
fix array overflow on receiving too many fragments for a packet").

The vulnerability could be triggered if the modem firmware sends packets
with excessive fragments. While under normal protocol conditions (MTU 3080
bytes, BAT buffer 3584 bytes),
a single packet should not require additional
fragments, the kernel should not blindly trust firmware behavior.
Malicious, buggy, or compromised firmware could potentially craft packets
with more fragments than the kernel expects.

Fix this by adding a bounds check before calling skb_add_rx_frag() to
ensure nr_frags does not exceed MAX_SKB_FRAGS.

The check must be performed before unmapping to avoid a page leak
and double DMA unmap during device teardown.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime), CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-23172?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23172?

Apply the vendor's patch.

## Is CVE-2026-23172 being exploited?

There is no known exploitation of CVE-2026-23172 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23172 and fix it if it is affected.

What it is: CVE-2026-23172 is a high-severity memory corruption vulnerability in Linux kernel, published on 14 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-23172 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-23172/ (Markdown: https://insights.sbomify.com/CVE-2026-23172/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23172
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23172
- OSV: https://osv.dev/vulnerability/CVE-2026-23172

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23172/
Summaries are generated and may contain mistakes; the official description above is the record.