# CVE-2026-68127: ila: reload IPv6 header after pskb_may_pull in checksum adjust

> Remote attackers can trigger a use-after-free in the Linux kernel ILA module via crafted IPv6 packets, potentially causing crashes or code execution.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Aug 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-68127, DEBIAN-CVE-2026-68127, GHSA-4hwh-2g43-5522, UBUNTU-CVE-2026-68127

## What is CVE-2026-68127?

CVE-2026-68127 is a critical use after free vulnerability in Linux, published on 10 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

ila: reload IPv6 header after pskb_may_pull in checksum adjust

ila_csum_adjust_transport() caches ip6h = ipv6_hdr(skb) before calling
pskb_may_pull(). On a non-linear skb whose transport header sits in a page
fragment, pskb_may_pull() can call __pskb_pull_tail() / pskb_expand_head()
and free the old skb head, leaving ip6h dangling; the following
get_csum_diff(ip6h, p) then reads freed memory. ila_update_ipv6_locator()
uses ip6h (and the iaddr derived from it) again after the csum-adjust
call and additionally writes the new locator through that pointer.

Impact: a remote IPv6 packet routed through a configured ILA
csum-adjust-transport route or receive-side mapping triggers a
slab-use-after-free in ila_update_ipv6_locator() (KASAN). The route or
mapping requires CAP_NET_ADMIN to configure, but trigger packets are
unauthenticated once it exists.

Reload ip6h after each pskb_may_pull() in ila_csum_adjust_transport()
before the csum-diff read. In ila_update_ipv6_locator() only the
ILA_CSUM_ADJUST_TRANSPORT case pulls the skb, so reload ip6h and iaddr in
that case alone before the destination-address write; the neutral-map
modes never pull and keep their cached pointers.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-68127?


## How do I fix CVE-2026-68127?

Apply the vendor's patch.

## Is CVE-2026-68127 being exploited?

There is no known exploitation of CVE-2026-68127 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68127 and fix it if it is affected.

What it is: CVE-2026-68127 is a critical use after free vulnerability in Linux, published on 10 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-68127 in the wild and no public exploit code.

Affected product: 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-2026-68127/ (Markdown: https://insights.sbomify.com/CVE-2026-68127/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68127
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68127
- OSV: https://osv.dev/vulnerability/CVE-2026-68127

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68127/
Summaries are generated and may contain mistakes; the official description above is the record.