# CVE-2025-38572: ipv6: reject malicious packets in ipv6_gso_segment()

> A crafted IPv6 packet with long extension headers causes an integer overflow in the Linux kernel, leading to a system crash.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Aug 2025
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-66527, AZL-73854, BELL-CVE-2025-38572, DEBIAN-CVE-2025-38572, GHSA-j327-57v5-q43v, ROOT-OS-DEBIAN-11-CVE-2025-38572, ROOT-OS-DEBIAN-12-CVE-2025-38572, ROOT-OS-DEBIAN-13-CVE-2025-38572, ROOT-OS-UBUNTU-2204-CVE-2025-38572, ROOT-OS-UBUNTU-2404-CVE-2025-38572, UBUNTU-CVE-2025-38572

## What is CVE-2025-38572?

CVE-2025-38572 is a high-severity vulnerability in Debian Debian Linux, published on 19 Aug 2025. 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:

ipv6: reject malicious packets in ipv6_gso_segment()

syzbot was able to craft a packet with very long IPv6 extension headers
leading to an overflow of skb->transport_header.

This 16bit field has a limited range.

Add skb_reset_transport_header_careful() helper and use it
from ipv6_gso_segment()

WARNING: CPU: 0 PID: 5871 at ./include/linux/skbuff.h:3032 skb_reset_transport_header include/linux/skbuff.h:3032 [inline]
WARNING: CPU: 0 PID: 5871 at ./include/linux/skbuff.h:3032 ipv6_gso_segment+0x15e2/0x21e0 net/ipv6/ip6_offload.c:151
Modules linked in:
CPU: 0 UID: 0 PID: 5871 Comm: syz-executor211 Not tainted 6.16.0-rc6-syzkaller-g7abc678e3084 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
 RIP: 0010:skb_reset_transport_header include/linux/skbuff.h:3032 [inline]
 RIP: 0010:ipv6_gso_segment+0x15e2/0x21e0 net/ipv6/ip6_offload.c:151
Call Trace:
 <TASK>
  skb_mac_gso_segment+0x31c/0x640 net/core/gso.c:53
  nsh_gso_segment+0x54a/0xe10 net/nsh/nsh.c:110
  skb_mac_gso_segment+0x31c/0x640 net/core/gso.c:53
  __skb_gso_segment+0x342/0x510 net/core/gso.c:124
  skb_gso_segment include/net/gso.h:83 [inline]
  validate_xmit_skb+0x857/0x11b0 net/core/dev.c:3950
  validate_xmit_skb_list+0x84/0x120 net/core/dev.c:4000
  sch_direct_xmit+0xd3/0x4b0 net/sched/sch_generic.c:329
  __dev_xmit_skb net/core/dev.c:4102 [inline]
  __dev_queue_xmit+0x17b6/0x3a70 net/core/dev.c:4679

## Which versions are affected by CVE-2025-38572?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-38572?

Apply the vendor's patch.

## Is CVE-2025-38572 being exploited?

There is no known exploitation of CVE-2025-38572 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-38572 and fix it if it is affected.

What it is: CVE-2025-38572 is a high-severity vulnerability in Debian Debian Linux, published on 19 Aug 2025. 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-2025-38572 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2025-38572/ (Markdown: https://insights.sbomify.com/CVE-2025-38572/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38572
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38572
- OSV: https://osv.dev/vulnerability/CVE-2025-38572

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38572/
Summaries are generated and may contain mistakes; the official description above is the record.