How severe is CVE-2017-11503?

CVE-2017-11503 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2017-11503 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-11503?

CVE-2017-11503 affects Phpmailer Project Phpmailer. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-11503?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2017-11503 published?

CVE-2017-11503 was published on 2017-07-20 and last updated on 2026-06-17.

CVE-2017-11503

CVE-2017-11503 is a medium-severity vulnerability in Phpmailer Project Phpmailer with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Phpmailer Project Phpmailer
Published: 2017-07-20
Last modified: 2026-06-17

Description

PHPMailer 5.2.23 has XSS in the "From Email Address" and "To Email Address" fields of code_generator.php.

Frequently asked questions

What is CVE-2017-11503?: PHPMailer 5.2.23 has XSS in the "From Email Address" and "To Email Address" fields of code_generator.php.
How severe is CVE-2017-11503?: CVE-2017-11503 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2017-11503 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-11503?: CVE-2017-11503 affects Phpmailer Project Phpmailer. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-11503?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-11503 published?: CVE-2017-11503 was published on 2017-07-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:phpmailer_project:phpmailer:5.2.23:*:*:*:*:*:*:*

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