HOMEVULNERABILITIESCVE-2026-27633
HIGH

CVE-2026-27633

CWE-400Published: February 26, 2026· Updated: Feb 28, 2026

7.5
CVSS v3.1
EPSS:0.10%probability of exploitation in 30 daysPercentile:26.5th

Official Description

TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32. Versions prior to version 2.02 have a Denial of Service (DoS) vulnerability via memory exhaustion. Unauthenticated remote attackers can send an HTTP POST request to the server with an exceptionally large `Content-Length` header (e.g., `2147483647`). The server continuously allocates memory for the request body (`EntityBody`) while streaming the payload without enforcing any maximum limit, leading to all available memory being consumed and causing the server to crash. Anyone hosting services using TinyWeb is impacted. Version 2.02 fixes the issue. The patch introduces a `CMaxEntityBodySize` limit (set to 10MB) for the maximum size of accepted payloads. As a temporary workaround if upgrading is not immediately possible, consider placing the server behind a Web Application Firewall (WAF) or reverse proxy (like nginx or Cloudflare) configured to explicitly limit the maximum allowed HTTP request body size (e.g., `client_max_body_size` in nginx).

NVD Source

Technical Analysis

CVE-2026-27633 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

ritlabs1 product
tinyweb
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/maximmasiutin/TinyWeb/commit/1cb5a1d
ADVISORYhttps://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-992w-gmcm-fmgr
ADVISORYhttps://www.masiutin.net/tinyweb-cve-2026-27633.html

All References (3)

→
https://github.com/maximmasiutin/TinyWeb/commit/1cb5a1dPatch
→
https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-992w-gmcm-fmgrVendor Advisory
→
https://www.masiutin.net/tinyweb-cve-2026-27633.htmlThird Party Advisory

Quick Facts

CVE IDCVE-2026-27633
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-400
CISA KEVNo
EPSS (30d)0.10%
Affected1 vendor
PublishedFeb 26, 2026

Related CVEs (CWE-400)

CVE-2026-30141
9.8
CVE-2026-8856
9.1
CVE-2026-7790
8.7
CVE-2026-45169
8.7
CVE-2025-32424
8.7
CVE-2026-33155
8.7

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-27633 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
← All Vulnerabilities·Search for CVE-2026-27633·NVD