# CVE-2026-76989: liftoff-sr CIPster TCP Encapsulation Receive Path encap.cc out-of-bounds

> Remote attackers can trigger an out-of-bounds read in the CIPster TCP encapsulation receive path, potentially exposing memory or causing crashes.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Aug 2026
- **Updated:** 25 Aug 2026
- **Also known as:** GHSA-q8vh-mhmw-wmcq

## What is CVE-2026-76989?

CVE-2026-76989 is a medium-severity memory corruption vulnerability in liftoff-sr CIPster, published on 20 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A security vulnerability has been detected in liftoff-sr CIPster 1802525be27d33e19a9a83c163e331a1d13b1892. This impacts an unknown function of the file source/src/enet_encap/encap.cc of the component TCP Encapsulation Receive Path. The manipulation leads to out-of-bounds read. The attack can be initiated remotely. The exploit has been disclosed publicly and may be used. The identifier of the patch is e8e9dba09bf56962807d3504b783ccdb6287f3e4. To fix this issue, it is recommended to deploy a patch.

Weakness: CWE-125 (Out-of-bounds Read), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-76989?


## How do I fix CVE-2026-76989?

No fix has been published for CVE-2026-76989 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-76989 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-76989 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-76989 and fix it if it is affected.

What it is: CVE-2026-76989 is a medium-severity memory corruption vulnerability in liftoff-sr CIPster, published on 20 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-76989 exists.

Affected product: liftoff-sr CIPster. 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-2026-76989/ (Markdown: https://insights.sbomify.com/CVE-2026-76989/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-76989
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-76989
- OSV: https://osv.dev/vulnerability/CVE-2026-76989

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-76989/
Summaries are generated and may contain mistakes; the official description above is the record.