# CVE-2024-26752: linux: In the Linux kernel, the following vulnerability has been resolved:  l2tp: pass correct message length to ip6_append_...

CVE-2024-26752 is fixed in linux on 1 platform, first by DEBIAN-CVE-2024-26752, released April 3, 2024. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2024-26752
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0025
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 3, 2024

## Description

In the Linux kernel, the following vulnerability has been resolved:  l2tp: pass correct message length to ip6_append_data  l2tp_ip6_sendmsg needs to avoid accounting for the transport header twice when splicing more data into an already partially-occupied skbuff.  To manage this, we check whether the skbuff contains data using skb_queue_empty when deciding how much data to append using ip6_append_data.  However, the code which performed the calculation was incorrect:       ulen = len + skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0;  ...due to C operator precedence, this ends up setting ulen to transhdrlen for messages with a non-zero length, which results in corrupted packets on the wire.  Add parentheses to correct the calculation in line with the original intent.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.82-1 | [DEBIAN-CVE-2024-26752](https://patchblox.com/security/data/fix/linux/debian-cve-2024-26752.md) | Apr 3, 2024 |
| Linux | linux Debian 13.5 (trixie) | 6.7.7-1 | [DEBIAN-CVE-2024-26752](https://patchblox.com/security/data/fix/linux/debian-cve-2024-26752.md) | Apr 3, 2024 |
| Linux | linux Debian 14 | 6.7.7-1 | [DEBIAN-CVE-2024-26752](https://patchblox.com/security/data/fix/linux/debian-cve-2024-26752.md) | Apr 3, 2024 |

---

Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.