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Public proof of conceptFix available

CVE-2017-5223

A public proof of concept exists; no exploitation attested.

  • Published2017-01-16
  • WeaknessCWE-200

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

An issue was discovered in PHPMailer before 5.2.22. PHPMailer's msgHTML method applies transformations to an HTML document to make it usable as an email message body. One of the transformations is to convert relative image URLs into attachments using a script-provided base directory. If no base directory is provided, it resolves to /, meaning that relative image URLs get treated as absolute local file paths and added as attachments. To form a remote vulnerability, the msgHTML method must be called, passed an unfiltered, user-supplied HTML document, and must not set a base directory.

Timeline

dates in UTC
  1. 2017-01-1606:59CVE publishedNVD
  2. 2026-10-2319:23First public proof of conceptPoC-in-GitHub

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2017-5223?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2017-5223?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV
Phpmailer project phpmailer
BranchAffectedFixed in
5.2≤ 5.2.21no fix published
phpmailer/phpmailer
BranchAffectedFixed in
5.x≥ 5.0.0, < 5.2.225.2.22

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

Detection

read 2026-10-23 19:23 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
EDB-43056
Exploit-DB
Proof-of-concept repositories
1 repository, unverifiedcscli/CVE-2017-5223
PoC-in-GitHub

Sources

  • NVDCVSS 3.05.5read 2026-10-23
  • NVDCVSS 2.02.1read 2026-10-23
  • NVDweakness (CWE)CWE-200read 2026-10-23
  • FIRST EPSSEPSS score2.1 %2026-10-23
  • PoC-in-GitHubproof of concept1read 2026-10-23
  • Exploit-DBdetectionread 2026-10-23
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Published
2017-01-16
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2017-5223?

An issue was discovered in PHPMailer before 5.2.22. PHPMailer's msgHTML method applies transformations to an HTML document to make it usable as an email message body. One of the transformations is to convert relative image URLs into attachments using a script-provided base directory. If no base directory is provided, it resolves to /, meaning that relative image URLs get treated as absolute local file paths and added as attachments. To form a remote vulnerability, the msgHTML method must be called, passed an unfiltered, user-supplied HTML document, and must not set a base directory.

Is CVE-2017-5223 actively exploited?

Active exploitation of CVE-2017-5223 has not been confirmed. Its EPSS score was 2.1% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2017-5223?

CVE-2017-5223 has a CVSS v3 base score of 5.5 (MEDIUM severity), with vector string CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

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