CVE-2026-29046Public exploitNetwork attack vector

CGI input injection via malformed HTTP headers

Published Mar 6, 2026 · Updated Mar 6, 2026

Header control-character injection in TinyWeb before 2.04 allows remote attackers to corrupt CGI input via crafted HTTP headers. The request parser accepts raw or percent-encoded CR, LF, and NUL in header values, and GetEnvStr copies those values into HTTP_* CGI environment variables. Exploitation is unauthenticated and network-reachable, but script-side injection or validation bypass requires a CGI program that trusts the tainted variable.

CVSS severity9.2
Critical
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Header control-character injection in TinyWeb before 2.04 allows remote attackers to corrupt CGI input via crafted HTTP headers. The request parser accepts raw or percent-encoded CR, LF, and NUL in header values, and GetEnvStr copies those values into HTTP_* CGI environment variables. Exploitation is unauthenticated and network-reachable, but script-side injection or validation bypass requires a CGI program that trusts the tainted variable.

The record

CVE
CVE-2026-29046
Published
Mar 6, 2026
Updated
Mar 6, 2026
Vendor
GeneralSandman
Product
TinyWeb
Classifications
CWE-114, CWE-20, CWE-93, CWE-74, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 6, 2026CVE publishedPublication date reported by the CVE source.
  2. 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.

  1. Affected versionversion=< 2.04

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GeneralSandman · TinyWebversion=< 2.04

Published CVSS scores

9.2GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L
8.8Maxim MasiutinCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L
8.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-114Process Control
CWE-20Improper Input Validation
CWE-93Improper Neutralization of CRLF Sequences ('CRLF Injection')
CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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