# CVE-2026-28318: SolarWinds Serv-U Uncontrolled Resource Consumption

> Unauthenticated attackers can crash the Serv-U service via crafted POST requests, requiring a patch to restore availability.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Yes, since 5 Jun 2026 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Jun 2026
- **Updated:** 21 Oct 2026
- **Also known as:** GHSA-4vx4-vp54-mwmc

## What is CVE-2026-28318?

CVE-2026-28318 is a high-severity denial of service vulnerability in Solarwinds Serv-U, published on 4 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

SolarWinds Serv-U is susceptible to specially crafted POST requests that crash the Serv-U service without authentication using Content-Encoding: deflate. Mitigation steps are provided to secure customer environments in the SolarWinds Trust Center if you are unable to deploy the update

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-28318?

It affects 1 product.


Products: Solarwinds Serv-U.

## How do I fix CVE-2026-28318?

No fix has been published for CVE-2026-28318 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 19 Jun 2026.

## Is CVE-2026-28318 being exploited?

Yes. Attackers have exploited CVE-2026-28318 in the wild since at least 5 Jun 2026.

Public exploit code:

- SolarWinds Serv-U CVE-2026-28318: unauthenticated Content-Encoding: deflate crash. Root-cause analysis (invalid free of an interior pointer -> heap corruption) + DoS-only PoC. Fixed in 15.5.4 Hotfix 1. (github_poc): https://github.com/EaEa0001/servu-cve-2026-28318-poc
- Safely detect whether a SolarWinds Serv-U host is vulnerable to CVE-2026-28318 (github_poc): https://github.com/BishopFox/CVE-2026-28318-check

## Other vulnerabilities in Solarwinds Serv-U

- [CVE-2021-35211](https://insights.sbomify.com/CVE-2021-35211/): SolarWinds Serv-U Remote Code Execution (critical 9.0, exploited in the wild)
- [CVE-2024-28995](https://insights.sbomify.com/CVE-2024-28995/): SolarWinds Serv-U Path Traversal Vulnerability (high 8.6, exploited in the wild)
- [CVE-2021-35247](https://insights.sbomify.com/CVE-2021-35247/): SolarWinds Serv-U Improper Input Validation (medium 4.3, exploited in the wild)
- [CVE-2020-35481](https://insights.sbomify.com/CVE-2020-35481/): Code injection in n/a (critical 9.8)
- [CVE-2026-28302](https://insights.sbomify.com/CVE-2026-28302/): SolarWinds Serv-U Insecure Direct Object Reference (IDOR) Vulnerability (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-28318 and fix it if it is affected.

What it is: CVE-2026-28318 is a high-severity denial of service vulnerability in Solarwinds Serv-U, published on 4 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2026-28318 in the wild since at least 5 Jun 2026.

Affected product: Solarwinds Serv-U. 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-2026-28318/ (Markdown: https://insights.sbomify.com/CVE-2026-28318/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-28318
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28318
- OSV: https://osv.dev/vulnerability/CVE-2026-28318

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-28318/
Summaries are generated and may contain mistakes; the official description above is the record.