How severe is CVE-2016-10034?

CVE-2016-10034 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2016-10034?

CVE-2016-10034 affects the following packages: zendframework/zend-mail (Packagist), zendframework/zend-mail (Packagist), zendframework/zend-mail (Packagist), zendframework/zend-mail (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2016-10034?

Update zendframework/zend-mail to 2.4.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-10034 is resolved across your whole dependency graph.

How do I detect CVE-2016-10034 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zendframework/zend-mail, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2016-10034 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2016-10034 actively exploited in the wild?

Yes. There are 5 known exploit references for CVE-2016-10034, including 3 documented proof-of-concept exploits on Exploit-DB and 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2016-10034?

CVE-2016-10034 has an EPSS (Exploit Prediction Scoring System) score of 38.4%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

What type of vulnerability is CVE-2016-10034?

CVE-2016-10034 is classified as CWE-77 (CWE-77). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2016-10034 published, and has it been updated?

CVE-2016-10034 was published on December 30, 2016 and was last updated on October 24, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

CRITICAL severity

CVE-2016-10034 — zend-mail

CRITICAL

CVE-2016-10034 is a critical-severity (CVSS 9.8) CWE-77 vulnerability in zendframework/zend-mail. 5 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for zendframework/zend-mail — see the affected versions and patch details below.

zend-mail remote code execution via Sendmail adapter

Also known asGHSA-r9mw-gwx9-v3h5

Published

Dec 30, 2016

Updated

Oct 24, 2026

Affected

4 pkgs

Patched

2 / 4

Exploits

5 known

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

38.4%probability of exploitation in next 30 days

Moderate Risk0.00%

Lower risk than most CVEs99th percentile — riskier than 99% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

4 pkgs affected

🐘zendframework/zend-mail🐘zendframework/zend-mail🐘zendframework/zend-mail🐘zendframework/zend-mail

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

The setFrom function in the Sendmail adapter in the zend-mail component before 2.4.11, 2.5.x, 2.6.x, and 2.7.x before 2.7.2, and Zend Framework before 2.4.11 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code via a " (backslash double quote) in a crafted e-mail address.

Affected Packages

4 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`zendframework/zend-mail`	all versions	2.4.11`composer require zendframework/zend-mail:^2.4.11`
🐘Packagist	`zendframework/zend-mail`	≥ 2.5	No fix
🐘Packagist	`zendframework/zend-mail`	≥ 2.6	No fix
🐘Packagist	`zendframework/zend-mail`	≥ 2.7&&< 2.7.2	2.7.2`composer require zendframework/zend-mail:^2.7.2`

Affected Products

2 products · 10 configurations

Application

zend frameworkzend

≤ 2.4.10

range

Application

zend-mailzend

≤ 2.4.10

8 versions

2.5.02.5.12.5.22.6.02.6.12.6.22.7.02.7.1

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-42221webappsphp

PHPMailer < 5.2.20 with Exim MTA - Remote Code Execution

by phackt_ul · Jun 21, 2017

Exploit-DB Source

EDB-40986webappsphp

PHPMailer < 5.2.20 / SwiftMailer < 5.4.5-DEV / Zend Framework / zend-mail < 2.4.11 - 'AIO' 'PwnScriptum' Remote Code Execution

by Dawid Golunski · Jan 2, 2017

Exploit-DB Source

EDB-40979webappsphp

Zend Framework / zend-mail < 2.4.11 - Remote Code Execution

by Dawid Golunski · Dec 30, 2016

Exploit-DB Source

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zendframework/zend-mail, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update zendframework/zend-mail to 2.4.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-10034 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

The setFrom function in the Sendmail adapter in the zend-mail component before 2.4.11, 2.5.x, 2.6.x, and 2.7.x before 2.7.2, and Zend Framework before 2.4.11 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code via a \" (backslash double quote) in a crafted e-mail address.

O3 Security · Impact-Aware SCA

Is CVE-2016-10034 in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

9.8/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Raw vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE Classification

CWE-77CWE-77

Weaponization

No Nuclei template or Metasploit module yet. 5 public proof-of-concept references are listed on this page.

Timeline

Disclosed

Dec 30, 2016

First exploit

Jun 21, 2017

Last updated

Oct 24, 2026

Identifiers

CVE-2016-10034

GHSA-r9mw-gwx9-v3h5

References

Advisorysecurityfocus.com Advisorysecurity.gentoo.org · 201804 10 Advisorynvd.nist.gov · CVE 2016 10034 Websecuritytracker.com Webexploit-db.com Webexploit-db.com Webexploit-db.com Webexploit-db.com Webexploit-db.com Webexploit-db.com Packagegithub.com · zend mail Evidenceframework.zend.com · ZF2016 04 Evidencelegalhackers.com · ZendFramework Exploit ZendMail Remote Code Exec CVE 2016 10034 Vuln

Related vulnerabilities

Also affects zendframework/zend-mail

This CVE is critical severity — higher than any of the other 1 CVE affecting zendframework/zend-mail (highest there: high).

GHSA-cxf7-m5g2-v594

Same weakness: CWE-77

This CVE is critical severity; 1 of 7 other CVEs with CWE-77 is rated as high or higher (top: critical).

CVE-2026-106765CVE-2026-106764CVE-2026-112942CVE-2026-102827CVE-2026-102826GHSA-jqmf-mx4f-hfr6CVE-2026-55182Browse all CWE-77

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 24, 2026

CVE-2016-10034 — zend-mail

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2016-10034 in your dependencies?