VulnerabilityAnalyzed

CVE-2026-29046

This can enable header value confusion across parser boundaries and may create unsafe data in the CGI execution context.

CRITICAL 9.2EPSS 0.39%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.39%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

TinyWeb is a web server (HTTP, HTTPS) written in Delphi for Win32. Prior to version 2.04, TinyWeb accepts request header values and later maps them into CGI environment variables (HTTP_*). The parser did not strictly reject dangerous control characters in header lines and header values, including CR, LF, and NUL, and did not consistently defend against encoded forms such as %0d, %0a, and %00. This can enable header value confusion across parser boundaries and may create unsafe data in the CGI execution context. This issue has been patched in version 2.04.

CVSS 4.0: 9.2 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.39% probability · 32th percentile
CISA KEV: Not listed
Weakness: CWE-20, CWE-74, CWE-93, CWE-114
Affected: ritlabs/tinyweb
Source: security-advisories@github.com

References

https://github.com/maximmasiutin/TinyWeb/commit/53aa8b6e5146491d7be57920e3fc50d7a34e4d5aPatch
https://github.com/maximmasiutin/TinyWeb/security/advisories/GHSA-r3gf-pg2c-m7mcExploit, Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.