# CVE-2026-27630: TinyWeb vulnerable to Remote Denial of Service via Thread/Connection Exhaustion (Slowloris)


- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 25 Feb 2026
- **Updated:** 26 Feb 2026
- **Also known as:** GHSA-ccv5-8948-c99c

## What is CVE-2026-27630?

CVE-2026-27630 is a high-severity vulnerability in maximmasiutin TinyWeb, published on 25 Feb 2026. 

### Official description

TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32. Versions prior to version 2.02 are vulnerable to a Denial of Service (DoS) attack known as Slowloris. The server spawns a new OS thread for every incoming connection without enforcing a maximum concurrency limit or an appropriate request timeout. An unauthenticated remote attacker can exhaust server concurrency limits and memory by opening numerous connections and sending data exceptionally slowly (e.g. 1 byte every few minutes). Anyone hosting services using TinyWeb is impacted. Version 2.02 fixes the issue. The patch introduces a `CMaxConnections` limit (set to 512) and a `CConnectionTimeoutSecs` idle timeout (set to 30 seconds). As a temporary workaround if upgrading is not immediately possible, consider placing the server behind a robust reverse proxy or Web Application Firewall (WAF) such as nginx, HAProxy, or Cloudflare, configured to buffer incomplete requests and aggressively enforce connection limits and timeouts.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-27630?

It affects 1 product.


Products: Ritlabs Tinyweb.

## How do I fix CVE-2026-27630?

No fix has been published for CVE-2026-27630 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-27630 being exploited?

There is no known exploitation of CVE-2026-27630 in the wild and no public exploit code.

## Other vulnerabilities in maximmasiutin TinyWeb

- [CVE-2026-27613](https://insights.sbomify.com/CVE-2026-27613/): CGI Parameter Injection (Bypass of STRICT_CGI_PARAMS and EscapeShellParam) (critical 10.0)
- [CVE-2026-22781](https://insights.sbomify.com/CVE-2026-22781/): TinyWeb CGI Command Injection (critical 10.0)
- [CVE-2026-28497](https://insights.sbomify.com/CVE-2026-28497/): TinyWeb: Integer Overflow in `_Val` (HTTP Request Smuggling) (critical 9.3)
- [CVE-2026-29046](https://insights.sbomify.com/CVE-2026-29046/): TinyWeb: HTTP Header Control Character Injection into CGI Environment (critical 9.2)
- [CVE-2026-27633](https://insights.sbomify.com/CVE-2026-27633/): TinyWeb has Unbounded Content-Length Memory Exhaustion (DoS) (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-27630 and fix it if it is affected.

What it is: CVE-2026-27630 is a high-severity vulnerability in maximmasiutin TinyWeb, published on 25 Feb 2026. 
Exploitation: There is no known exploitation of CVE-2026-27630 in the wild and no public exploit code.

Affected product: maximmasiutin TinyWeb. 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-2026-27630/ (Markdown: https://insights.sbomify.com/CVE-2026-27630/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-27630
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-27630
- OSV: https://osv.dev/vulnerability/CVE-2026-27630

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-27630/
Summaries are generated and may contain mistakes; the official description above is the record.