# CVE-2026-48688: Memory corruption in n/a

> FastNetMon Community Edition suffers from out-of-bounds reads in BGP IPv6 decoding, allowing attackers to cause denial of service or disclose memory.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 May 2026
- **Updated:** 26 May 2026
- **Also known as:** DEBIAN-CVE-2026-48688, GHSA-rxgw-72v4-4rvj, UBUNTU-CVE-2026-48688

## What is CVE-2026-48688?

CVE-2026-48688 is a high-severity memory corruption vulnerability in n/a, published on 26 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

FastNetMon Community Edition through 1.2.9 contains multiple out-of-bounds reads in the BGP MP_REACH_NLRI IPv6 attribute decoder. The function decode_mp_reach_ipv6() in src/bgp_protocol.cpp contains a TODO comment at line 156 explicitly acknowledging 'we should add sanity checks to avoid reads after attribute memory block.' The function casts raw pointers to structure types without verifying sufficient data exists (line 158), uses the attacker-controlled length_of_next_hop field to determine memcpy size (line 181), and computes prefix_length by dereferencing a pointer calculated from multiple attacker-controlled offsets without bounds validation (line 189). The prefix_length is then used to calculate number_of_bytes_required_for_prefix which becomes a memcpy length (line 202) with no check against remaining buffer size.

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

## Which versions are affected by CVE-2026-48688?

It affects 1 product.


Products: Pavel-Odintsov Fastnetmon.

## How do I fix CVE-2026-48688?

Apply the vendor's patch.

## Is CVE-2026-48688 being exploited?

There is no known exploitation of CVE-2026-48688 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2026-48686](https://insights.sbomify.com/CVE-2026-48686/): Memory corruption in n/a (critical 9.8)
- [CVE-2026-48689](https://insights.sbomify.com/CVE-2026-48689/): Memory corruption in n/a (critical 9.8)
- [CVE-2026-48687](https://insights.sbomify.com/CVE-2026-48687/): Command injection in n/a (high 8.1)
- [CVE-2026-48692](https://insights.sbomify.com/CVE-2026-48692/): Missing authorization in n/a (high 8.1)
- [CVE-2026-48694](https://insights.sbomify.com/CVE-2026-48694/): Command injection in n/a (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-48688 and fix it if it is affected.

What it is: CVE-2026-48688 is a high-severity memory corruption vulnerability in n/a, published on 26 May 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-2026-48688 in the wild and no public exploit code.

Affected product: n/a. 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-2026-48688/ (Markdown: https://insights.sbomify.com/CVE-2026-48688/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48688
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48688
- OSV: https://osv.dev/vulnerability/CVE-2026-48688

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-48688/
Summaries are generated and may contain mistakes; the official description above is the record.