# CVE-2026-90558: sngrep through 1.8.4 Stack Buffer Overflow via SIP Headers

> Attackers can execute arbitrary code or cause denial of service in sngrep by sending malicious SIP packets with oversized headers.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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:** Yes
- **Published:** 12 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-90558, GHSA-5vq7-hmwf-89w5, UBUNTU-CVE-2026-90558, openSUSE-SU-2026:11791-1

## What is CVE-2026-90558?

CVE-2026-90558 is a critical memory corruption vulnerability in irontec sngrep, published on 12 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

sngrep through 1.8.4 contains stack buffer overflow vulnerabilities in SIP attribute formatting routines when header values exceed the 255-byte buffer limit. Attackers can craft malicious SIP packets with oversized Call-ID, X-Call-ID, or other header fields to overflow stack buffers and cause crashes or execute arbitrary code during packet parsing and rendering.

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2026-90558?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `sngrep` | openSUSE:Tumbleweed | All versions | 1.8.4-2.1 |

## How do I fix CVE-2026-90558?

Apply the vendor's patch.

## Is CVE-2026-90558 being exploited?

There is no known exploitation of CVE-2026-90558 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90558 and fix it if it is affected.

What it is: CVE-2026-90558 is a critical memory corruption vulnerability in irontec sngrep, published on 12 Sep 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-2026-90558 in the wild and no public exploit code.

Affected product: irontec sngrep. 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-2026-90558/ (Markdown: https://insights.sbomify.com/CVE-2026-90558/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90558
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90558
- OSV: https://osv.dev/vulnerability/CVE-2026-90558

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90558/
Summaries are generated and may contain mistakes; the official description above is the record.