What is CVE-2026-77634?

CVE-2026-77634 is a high-severity security vulnerability in cakephp/cakephp (composer), affecting versions >= 4.5.0, < 4.5.12. It is fixed in 4.5.12, 4.6.5, 5.1.9, 5.2.14, 5.3.7.

Which versions of cakephp/cakephp are affected by CVE-2026-77634?

cakephp/cakephp (composer) versions >= 4.5.0, < 4.5.12 is affected.

Is there a fix for CVE-2026-77634?

Yes. CVE-2026-77634 is fixed in 4.5.12, 4.6.5, 5.1.9, 5.2.14, 5.3.7. Upgrade to this version or later.

Is CVE-2026-77634 exploitable, and should I be worried?

Whether CVE-2026-77634 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2026-77634 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2026-77634?

Upgrade: cakephp/cakephp to 4.5.12 or later, cakephp/cakephp to 4.6.5 or later, cakephp/cakephp to 5.1.9 or later, cakephp/cakephp to 5.2.14 or later, cakephp/cakephp to 5.3.7 or later.

CVE-2026-77634 in cakephp/cakephp

Q: Which versions of cakephp/cakephp are affected by CVE-2026-77634?

cakephp/cakephp (composer) versions >= 4.5.0, < 4.5.12 is affected.

Q: Is there a fix for CVE-2026-77634?

Yes. CVE-2026-77634 is fixed in 4.5.12, 4.6.5, 5.1.9, 5.2.14, 5.3.7. Upgrade to this version or later.

Q: Is CVE-2026-77634 exploitable, and should I be worried?

Whether CVE-2026-77634 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2026-77634 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2026-77634?

Upgrade: cakephp/cakephp to 4.5.12 or later, cakephp/cakephp to 4.6.5 or later, cakephp/cakephp to 5.1.9 or later, cakephp/cakephp to 5.2.14 or later, cakephp/cakephp to 5.3.7 or later.

Summary

CakePHP: SmtpTransport vulnerable to CRLF header injection

Workarounds

You can strip CRLF bytes from email header values before setting header values.

Impact

Custom mail headers added with Message::setHeaders() or addHeaders() do not have CRLF replaced allowing header injection if user controlled data is added to message headers without stripping CRLF bytes.

Affected versions

cakephp/cakephp (>= 4.5.0, < 4.5.12) cakephp/cakephp (>= 4.6.0, < 4.6.5) cakephp/cakephp (>= 5.0.0, < 5.1.8) cakephp/cakephp (>= 5.2.0, < 5.2.14) cakephp/cakephp (>= 5.3.0, < 5.3.7)

Security releases

cakephp/cakephp → 4.5.12 (composer) cakephp/cakephp → 4.6.5 (composer) cakephp/cakephp → 5.1.9 (composer) cakephp/cakephp → 5.2.14 (composer) cakephp/cakephp → 5.3.7 (composer)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

Already deployed Kodem?

See it in your environment New to Kodem? Get a demo →

Remediation advice

5.3.7, 5.2.14, 5.1.9, 4.6.5, 4.5.12 contain fixes for this issue.

Frequently Asked Questions

What is CVE-2026-77634? CVE-2026-77634 is a high-severity security vulnerability in cakephp/cakephp (composer), affecting versions >= 4.5.0, < 4.5.12. It is fixed in 4.5.12, 4.6.5, 5.1.9, 5.2.14, 5.3.7.
Which versions of cakephp/cakephp are affected by CVE-2026-77634? cakephp/cakephp (composer) versions >= 4.5.0, < 4.5.12 is affected.
Is there a fix for CVE-2026-77634? Yes. CVE-2026-77634 is fixed in 4.5.12, 4.6.5, 5.1.9, 5.2.14, 5.3.7. Upgrade to this version or later.
Is CVE-2026-77634 exploitable, and should I be worried? Whether CVE-2026-77634 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2026-77634 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2026-77634?
- Upgrade cakephp/cakephp to 4.5.12 or later
- Upgrade cakephp/cakephp to 4.6.5 or later
- Upgrade cakephp/cakephp to 5.1.9 or later
- Upgrade cakephp/cakephp to 5.2.14 or later
- Upgrade cakephp/cakephp to 5.3.7 or later