CVE-2026-55618Network attack vector

URL inspection bypass via pre-decoding validation

Published Aug 25, 2026 · Updated Aug 28, 2026

URL extraction bypass in GOVCERT.LU eml_parser before 3.0.2 allows remote attackers to hide malicious links in email via HTML entities. The clean_found_uri function in eml_parser/parser.py validates candidate URLs before decoding entity-encoded colons, slashes, and periods, so it discards valid URLs and hosts. Exploitation requires a crafted email to be processed; pipelines relying on the omitted IOC lists fail to submit those links to reputation or sandbox analysis.

CVSS severity6.5
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

URL extraction bypass in GOVCERT.LU eml_parser before 3.0.2 allows remote attackers to hide malicious links in email via HTML entities. The clean_found_uri function in eml_parser/parser.py validates candidate URLs before decoding entity-encoded colons, slashes, and periods, so it discards valid URLs and hosts. Exploitation requires a crafted email to be processed; pipelines relying on the omitted IOC lists fail to submit those links to reputation or sandbox analysis.

The record

CVE
CVE-2026-55618
Published
Aug 25, 2026
Updated
Aug 28, 2026
Vendor
GOVCERT.LU
Product
eml_parser
Classifications
CWE-116, T1027
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 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=< 3.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GOVCERT.LU · eml_parserversion=< 3.0.2

Published CVSS scores

6.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-116Improper Encoding or Escaping of Output
T1027Obfuscated Files or Information

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

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Your stack

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