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CVE-2018-19296· NVD / CVE Program· CNA mitre

PHPMailer before 5.2.27 and 6.x before 6.0.6 is vulnerable to an object injection attack.

HighCVSS 8.8 · v3.1—No exploit Fix available
Published
Nov 16, 2018
Updated
Jun 16, 2026
EPSS
2.2% · 82th percentile
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Report tools

JSON

Action score

36

Monitor

Low priority for now.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.2%

Affected systems

VendorProduct
phpmailer projectphpmailer
debiandebian linux
fedoraprojectfedora
wordpresswordpress

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • wordpress wordpress3.7 and later · up to 5.7 inclusive

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12libphp-phpmailerbefore 5.2.14+dfsg-2.45.2.14+dfsg-2.4
Debian:8libphp-phpmailerbefore 5.2.9+dfsg-2+deb8u45.2.9+dfsg-2+deb8u4
Debian:9libphp-phpmailerbefore 5.2.14+dfsg-2.3+deb9u15.2.14+dfsg-2.3+deb9u1
Packagistphpmailer/phpmailerfrom 5.0.0 · before 5.2.275.2.27
Packagistphpmailer/phpmailerfrom 6.0.0 · before 6.0.66.0.6

Same product

phpmailer project: all records

Other highest-scoring records for the same primary product.

  • CVE-2016-10033The mailSend function in the isMail transport in PHPMailer before 5.2.18 might allow remote attackers to pass extra parameters to the mail cKEV
    99Now
  • CVE-2016-10045The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently e
    68This week
  • CVE-2020-36326PHPMailer 6.1.8 through 6.4.0 allows object injection through Phar Deserialization via addAttachment with a UNC pathname.
    40Plan
  • CVE-2021-3603Inclusion of Functionality from Untrusted Control Sphere in PHPMailer/PHPMailer
    33Monitor
  • CVE-2021-34551PHPMailer before 6.5.0 on Windows allows remote code execution if lang_path is untrusted data and has a UNC pathname.
    33Monitor
  • CVE-2020-13625PHPMailer before 6.1.6 contains an output escaping bug when the name of a file attachment contains a double quote character.
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:libphp-phpmailer5.2.14+dfsg-2.4 · Debian:12Package registry (OSV)
Packagist:phpmailer/phpmailer5.2.27Package registry (OSV)
Packagist:phpmailer/phpmailer6.0.6Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-502 · Deserialization of Untrusted Data

CVSS vector

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

nvd-primary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

The bug in code

The whole CWE-502 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python
payload = sock.recv(65536)job = pickle.loads(payload)

Fixed

python
payload = sock.recv(65536)if not hmac.compare_digest(sign(payload), header_sig):    raise PermissionError("invalid signature")job = JobSchema.validate(json.loads(payload))

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

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Change log

  1. Fix✗ → ✓

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References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records