CVE-2022-4993

Resource exhaustion via error-message template injection

Published Aug 13, 2026 · Updated Aug 13, 2026

Template injection in HTML::FormHandler 0 through 0.40068 allows attackers to exhaust resources or dispatch selected methods. add_error treats request-derived warning, constraint, exception, or validator text as a Locale::Maketext message key, and the _AUTO lexicon compiles unknown keys as bracket-notation templates. Exposure requires application code to process an untrusted field through an affected path; malformed templates make process() throw, while crafted sprintf widths drive attacker-chosen memory allocation.

CVSS severityUnavailable
Unscored
EPSS probability0.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Template injection in HTML::FormHandler 0 through 0.40068 allows attackers to exhaust resources or dispatch selected methods. add_error treats request-derived warning, constraint, exception, or validator text as a Locale::Maketext message key, and the _AUTO lexicon compiles unknown keys as bracket-notation templates. Exposure requires application code to process an untrusted field through an affected path; malformed templates make process() throw, while crafted sprintf widths drive attacker-chosen memory allocation.

The record

CVE
CVE-2022-4993
Published
Aug 13, 2026
Updated
Aug 13, 2026
Vendor
FormHandler Contributors
Product
HTML-FormHandler
Classifications
CWE-1336, CWE-470, T1499.003
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Aug 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=0.40068

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

FormHandler Contributors · HTML-FormHandlerversion=0 <=0.40068

Published CVSS scores

No CVSS assessment is available in this record.

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)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1336Improper Neutralization of Special Elements Used in a Template Engine
CWE-470Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
T1499.003Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo