Unauthenticated request smuggling via Content-Length overflow
Published Mar 6, 2026 · Updated Mar 6, 2026
Integer overflow in GeneralSandman TinyWeb before 2.03 allows remote attackers to smuggle requests via oversized Content-Length values. The _Val routine in SRC/xBase.pas accumulates Content-Length digits in a signed 32-bit integer without checking overflow, so TinyWeb reads a wrapped body length and parses buffered bytes as another request. Exploitation requires no authentication or user interaction, while request desynchronization requires a persistent connection and can bypass frontend filtering, poison cached responses, or expose another user's request data.
Summary
What happened
Integer overflow in GeneralSandman TinyWeb before 2.03 allows remote attackers to smuggle requests via oversized Content-Length values. The _Val routine in SRC/xBase.pas accumulates Content-Length digits in a signed 32-bit integer without checking overflow, so TinyWeb reads a wrapped body length and parses buffered bytes as another request. Exploitation requires no authentication or user interaction, while request desynchronization requires a persistent connection and can bypass frontend filtering, poison cached responses, or expose another user's request data.
The record
- CVE
- CVE-2026-28497
- Published
- Mar 6, 2026
- Updated
- Mar 6, 2026
- Vendor
- GeneralSandman
- Product
- TinyWeb
- Classifications
- CWE-444, CWE-190, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 6, 2026CVE publishedPublication date reported by the CVE source.
- Mar 6, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.03
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-rp8j-cx7r-mw9f embedded request-smuggling proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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