# CVE-2026-108103: Open5GS through 2.8.0 Heap Out-of-Bounds Read via PFCP Dropped DL Traffic Threshold IE

> Remote attackers can trigger a heap out-of-bounds read in Open5GS UPF via crafted PFCP requests, leading to information disclosure or service 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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Oct 2026
- **Updated:** 14 Oct 2026
- **Also known as:** GHSA-4rxj-63ch-hjqf

## What is CVE-2026-108103?

CVE-2026-108103 is a medium-severity memory corruption vulnerability in open5gs, published on 9 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Open5GS through 2.8.0 contains a heap out-of-bounds read vulnerability in ogs_pfcp_parse_dropped_dl_traffic_threshold() that allows remote unauthenticated attackers to read past IE buffers via short IEs. Attackers can send PFCP Session Establishment or Modification Requests to the UPF on UDP port 8805 with DLPA and DLBY flags set, potentially crashing the UPF.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-108103?


## How do I fix CVE-2026-108103?

No fix has been published for CVE-2026-108103 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-108103 being exploited?

There is no known exploitation of CVE-2026-108103 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-108103 and fix it if it is affected.

What it is: CVE-2026-108103 is a medium-severity memory corruption vulnerability in open5gs, published on 9 Oct 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-2026-108103 in the wild and no public exploit code.

Affected product: open5gs. 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-2026-108103/ (Markdown: https://insights.sbomify.com/CVE-2026-108103/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-108103
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-108103
- OSV: https://osv.dev/vulnerability/CVE-2026-108103

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-108103/
Summaries are generated and may contain mistakes; the official description above is the record.