# CVE-2022-49728: ipv6: Fix signed integer overflow in __ip6_append_data

> A signed integer overflow in the Linux kernel IPv6 stack can cause a crash, requiring a patch to fix the variable type.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 26 Feb 2025
- **Updated:** 11 May 2026
- **Also known as:** AZL-58045, DEBIAN-CVE-2022-49728, GHSA-cwf6-gj87-3ghq, UBUNTU-CVE-2022-49728

## What is CVE-2022-49728?

CVE-2022-49728 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 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: Fix signed integer overflow in __ip6_append_data

Resurrect ubsan overflow checks and ubsan report this warning,
fix it by change the variable [length] type to size_t.

UBSAN: signed-integer-overflow in net/ipv6/ip6_output.c:1489:19
2147479552 + 8567 cannot be represented in type 'int'
CPU: 0 PID: 253 Comm: err Not tainted 5.16.0+ #1
Hardware name: linux,dummy-virt (DT)
Call trace:
  dump_backtrace+0x214/0x230
  show_stack+0x30/0x78
  dump_stack_lvl+0xf8/0x118
  dump_stack+0x18/0x30
  ubsan_epilogue+0x18/0x60
  handle_overflow+0xd0/0xf0
  __ubsan_handle_add_overflow+0x34/0x44
  __ip6_append_data.isra.48+0x1598/0x1688
  ip6_append_data+0x128/0x260
  udpv6_sendmsg+0x680/0xdd0
  inet6_sendmsg+0x54/0x90
  sock_sendmsg+0x70/0x88
  ____sys_sendmsg+0xe8/0x368
  ___sys_sendmsg+0x98/0xe0
  __sys_sendmmsg+0xf4/0x3b8
  __arm64_sys_sendmmsg+0x34/0x48
  invoke_syscall+0x64/0x160
  el0_svc_common.constprop.4+0x124/0x300
  do_el0_svc+0x44/0xc8
  el0_svc+0x3c/0x1e8
  el0t_64_sync_handler+0x88/0xb0
  el0t_64_sync+0x16c/0x170

Changes since v1:
-Change the variable [length] type to unsigned, as Eric Dumazet suggested.
Changes since v2:
-Don't change exthdrlen type in ip6_make_skb, as Paolo Abeni suggested.
Changes since v3:
-Don't change ulen type in udpv6_sendmsg and l2tp_ip6_sendmsg, as
Jakub Kicinski suggested.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2022-49728?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49728?

Apply the vendor's patch.

## Is CVE-2022-49728 being exploited?

There is no known exploitation of CVE-2022-49728 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-2022-49728 and fix it if it is affected.

What it is: CVE-2022-49728 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 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-2022-49728 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-2022-49728/ (Markdown: https://insights.sbomify.com/CVE-2022-49728/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49728
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49728
- OSV: https://osv.dev/vulnerability/CVE-2022-49728

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49728/
Summaries are generated and may contain mistakes; the official description above is the record.