CVE-2026-77634: CakePHP: SmtpTransport vulnerable to CRLF header injection

Severity: high (CVSS 8.2 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-24 · updated 2026-10-12
Weakness: CWE-93

Description

CakePHP is a rapid development framework for PHP. Prior to versions 4.5.12, 4.6.5, 5.1.8, 5.2.14, and 5.3.7 on their respective release lines, custom mail headers added with Message::setHeaders() or Message::addHeaders() do not have CRLF bytes removed, allowing header injection when user-controlled data is used in message headers. This issue is fixed in versions 4.5.12, 4.6.5, 5.1.8, 5.2.14, and 5.3.7.

Affected products

cakephp: from 4.5.0, < 4.5.12; from 4.6.0, < 4.6.5; from 5.0.0, < 5.1.9; from 5.2.0, < 5.2.14; from 5.3.0, < 5.3.7

References

https://github.com/cakephp/cakephp/commit/08188962bcd99a95da1e49f62e786f2d688f1e41
https://github.com/cakephp/cakephp/commit/2afe42b02d8ddc5d442bca5e8bb61910a727646e
https://github.com/cakephp/cakephp/commit/3e09dae6cbdc983754fa3a8e6aae74da102a3ea1
https://github.com/cakephp/cakephp/commit/b67b622457362b075bb37e625a82af73a0b3c9c3
https://github.com/cakephp/cakephp/security/advisories/GHSA-2qh5-382h-3jpc

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