Security readout for executives and security teams
Plain-English summary
CVE-2026-27633 is a denial-of-service flaw in TinyWeb before 2.02. A remote unauthenticated user can make the server consume memory until it crashes. This affects organizations hosting services with TinyWeb. The vendor-provided fix is version 2.02, which adds a maximum request body size.
Executive priority
Treat as high priority for internet-facing TinyWeb services because it can cause outage without authentication. Prioritize confirming use of TinyWeb, upgrading to 2.02, or enforcing request body limits through a front-end control until upgrade is complete.
Technical view
TinyWeb before 2.02 does not enforce a maximum EntityBody size when processing HTTP POST requests with very large Content-Length values. The server keeps allocating memory while receiving the body, causing memory exhaustion and crash. The issue is classified as CWE-400 and has CVSS 4.0 score 8.7, with network attack vector and no privileges required.
Likely exposure
Exposure is limited to systems running TinyWeb versions earlier than 2.02, especially internet-facing HTTP or HTTPS services. Anyone hosting services using TinyWeb is described as impacted. Environments not using TinyWeb are not affected based on the provided sources.
Exploitation context
The sources describe unauthenticated remote denial of service through oversized HTTP request bodies. CISA KEV status is false in the provided bundle, and no cited source states active exploitation. The practical impact is service outage from process crash or host memory pressure.
Researcher notes
The public advisory and CVE record identify the root cause as unbounded request body allocation. The referenced commit introduces CMaxEntityBodySize set to 10MB. Do not assume broader product impact beyond TinyWeb before 2.02 based on the available sources.
Mitigation direction
- Upgrade TinyWeb to version 2.02 or later.
- If upgrade is delayed, place TinyWeb behind a WAF or reverse proxy.
- Configure explicit maximum HTTP request body size limits at the proxy.
- Monitor vendor advisory and project repository for additional guidance.
Validation and detection
- Inventory systems running TinyWeb and record versions.
- Confirm any TinyWeb instance below 2.02 is prioritized for remediation.
- Check reverse proxy or WAF request body size limits.
- Review service monitoring for unexplained TinyWeb crashes or memory exhaustion.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-400: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-27633 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.7 (4.0)
- Known Exploited
- No
- Published
Vector: 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
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
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——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
8.7HighVector: 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
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-992w-gmcm-fmgrCVE reference · x_refsource_CONFIRM
- https://github.com/maximmasiutin/TinyWeb/commit/1cb5a1dCVE reference · x_refsource_MISC
- https://www.masiutin.net/tinyweb-cve-2026-27633.htmlCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.