The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code by leveraging improper interaction between the escapeshellarg function and internal escaping performed in the mail function in PHP. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-10033.
CVE-2016-10045
This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 98.0%, top 0% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- 1,426 internet-exposed hosts are running an affected version right now
- High exploitation likelihood — EPSS 98%
- Public exploit code is available (Metasploit, epss top5pct, epss high, public exploit)
A fix is available — apply it.
1,426 internet-exposed hosts are running an affected version of CVE-2016-10045 right now.
EchelonGraph is the only CVE feed that fuses live vulnerability intelligence with its own live internet-exposure radar — so you see not just that a CVE is exploited, but how much of the internet is exposed to it right now.
- CVSS v3
- 9.8
- EG Score
- 9.8(low)
- EG Risk
- 88(Track*)EG Risk 88/100SSVC: Track*
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity98% × 45%Exploitation98% × 40%Automatability30% × 15%Action: Watch closely — could escalate to Attend. - EPSS PROB
- 98%
- EPSS %ILE
- 100%
- KEV
- Not listed
Published
December 30, 2016
Last Modified
June 17, 2026
Advisory Details (10)
Auto-updated Sep 16, 2026PHPMailer 5.2.20
Patch available: PHPMailer/PHPMailer v5.2.20
https://github.com/PHPMailer/PHPMailer/releases/tag/v5.2.20[20161205] - PHPMailer Security Advisory
https://developer.joomla.org/security-centre/668-20161205-phpmailer-security-advisory.htmlPHPMailer Sendmail Argument Injection | Metasploit Module
http://www.rapid7.com/db/modules/exploit/multi/http/phpmailer_arg_injectionFull Disclosure: PHPMailer < 5.2.20 Remote Code Execution PoC 0day Exploit (CVE-2016-10045) (Bypass of the CVE-2016-1033 patch)
http://seclists.org/fulldisclosure/2016/Dec/81Locked Out | Packet Storm
http://packetstormsecurity.com/files/140350/PHPMailer-Sendmail-Argument-Injection.htmlLocked Out | Packet Storm
http://packetstormsecurity.com/files/140286/PHPMailer-Remote-Code-Execution.htmloss-security - Re: PHPMailer < 5.2.18 Remote Code Execution [updated advisory] [CVE-2016-10033]
http://openwall.com/lists/oss-security/2016/12/28/1Patch Availability(1)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | libphp-phpmailer (6.0.6-0.1ubuntu0.1~esm1) @ focal | 2026-05-20 | ubuntu |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(5 across 5 ecosystems)
Alpine:v3.2(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| php-phpmailer | 5.2.0-r0 | 5.2.4-r0 | — |
Alpine:v3.3(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| php-phpmailer | 5.2.0-r0 | 5.2.4-r0 | — |
Alpine:v3.4(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| php5-phpmailer | 5.2.0-r0 | 5.2.0-r1 | — |
Alpine:v3.5(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| php5-phpmailer | 5.2.0-r0, 5.2.4-r0 | 5.2.4-r1 | — |
Packagist(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| phpmailer/phpmailer | v5.2.10 ... v5.2.9 (17 versions) | 5.2.20 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(1)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
Data Freshness Timeline
(refreshed 3× in last 7d / 7× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-09-17 19:21 UTCEPSS rescore
- 2026-09-15 03:05 UTCEPSS rescore
- 2026-09-15 01:14 UTCOSV refresh
- 2026-09-10 09:26 UTCEPSS rescore
- 2026-09-06 13:42 UTCEPSS rescore
- 2026-08-27 01:00 UTCOSV refresh
- 2026-08-26 14:41 UTCEPSS rescore
- 2026-08-19 16:59 UTCEPSS rescore
- 2026-08-16 02:09 UTCEPSS rescore
- 2026-08-15 01:25 UTCEPSS rescore
- 2026-08-10 14:38 UTCOSV refresh
- 2026-08-08 16:32 UTCEPSS rescore
- 2026-08-06 13:42 UTCEPSS rescore
- 2026-08-05 19:12 UTCEPSS rescore
- 2026-07-30 01:26 UTCEPSS rescore
- 2026-07-30 01:26 UTCEPSS rescore
- 2026-07-28 15:31 UTCEPSS rescore
- 2026-07-25 15:30 UTCOSV refresh
- 2026-07-24 14:13 UTCEPSS rescore
- 2026-07-23 01:21 UTCEG score recompute
- 2026-07-23 00:22 UTCEG score recompute
- 2026-07-22 22:00 UTCEG score recompute
- 2026-07-15 16:54 UTCEPSS rescore
- 2026-07-15 16:54 UTCEPSS rescore
- 2026-07-09 19:05 UTCEPSS rescore
Show 33 moreShow fewer
- 2026-07-09 19:05 UTCEPSS rescore
- 2026-07-08 10:05 UTCOSV refresh
- 2026-07-07 13:42 UTCEPSS rescore
- 2026-07-07 13:42 UTCEPSS rescore
- 2026-07-04 06:28 UTCEPSS rescore
- 2026-06-19 22:06 UTCOSV refresh
- 2026-06-15 17:45 UTCEPSS rescore
- 2026-06-12 23:09 UTCEPSS rescore
- 2026-06-12 23:09 UTCEPSS rescore
- 2026-06-06 13:45 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-02 20:10 UTCEPSS rescore
- 2026-05-31 01:25 UTCOSV refresh
- 2026-05-27 13:38 UTCEPSS rescore
- 2026-05-27 13:38 UTCEPSS rescore
- 2026-05-26 07:16 UTCEPSS rescore
- 2026-05-26 07:16 UTCEPSS rescore
- 2026-05-22 21:15 UTCEPSS rescore
- 2026-05-21 22:40 UTCEPSS rescore
- 2026-05-20 10:17 UTCVendor advisory
- 2026-05-20 06:39 UTCVendor advisory
- 2026-05-20 03:01 UTCVendor advisory
- 2026-05-19 23:23 UTCVendor advisory
- 2026-05-19 19:44 UTCVendor advisory
- 2026-05-19 16:06 UTCVendor advisory
- 2026-05-19 12:22 UTCVendor advisory
- 2026-05-19 07:56 UTCVendor advisory
- 2026-05-19 04:18 UTCVendor advisory
- 2026-05-19 00:37 UTCEG score recompute
- 2026-05-19 00:37 UTCVendor advisory
- 2026-05-18 21:30 UTCEPSS rescore
- 2026-05-18 21:30 UTCEPSS rescore
Publicly available exploits
(4 references)Working exploit code is in the public domain (1 Metasploit module) (3 Exploit-DB entries). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- Exploit-DBEDB-42221First seen Jun 21, 2017
PHPMailer < 5.2.20 with Exim MTA - Remote Code Execution
Open source ↗ - Exploit-DBEDB-40986First seen Jan 2, 2017
PHPMailer < 5.2.20 / SwiftMailer < 5.4.5-DEV / Zend Framework / zend-mail < 2.4.11 - 'AIO' 'PwnScriptum' Remote Code Execution
Open source ↗ - Exploit-DBEDB-40969First seen Dec 27, 2016
PHPMailer < 5.2.20 - Remote Code Execution
Open source ↗ - Metasploitexploit/multi/http/phpmailer_arg_injection✓ verifiedFirst seen Dec 26, 2016
PHPMailer Sendmail Argument Injection
Open source ↗
Frequently asked(5)
What is CVE-2016-10045?
When was CVE-2016-10045 disclosed?
Is CVE-2016-10045 actively exploited?
What is the CVSS score of CVE-2016-10045?
How do I remediate CVE-2016-10045?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2016-10045
Is Your Infrastructure Affected by CVE-2016-10045?
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