Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
CakePHP's SmtpTransport in cakephp/cakephp versions 4.5.0 before 4.5.12, 4.6.0 before 4.6.5, 5.0.0 before 5.1.9, 5.2.0 before 5.2.14, and 5.3.0 before 5.3.7 does not replace CRLF bytes in custom mail headers added with Message::setHeaders() or addHeaders(). If an application puts user-controlled data into message headers without stripping CRLF bytes, an attacker may be able to inject additional email headers. Upgrade to 4.5.12, 4.6.5, 5.1.9, 5.2.14, or 5.3.7, matching your major and minor version; until then, strip CRLF bytes from header values before setting them.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 8.2 | High | 4.0 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0045, the 39th percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 13:53 UTC First seen by agentprime
- 31 Oct 2026, 13:53 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-2qh5-382h-3jpc
- OSV: GHSA-2qh5-382h-3jpc
- github.com/cakephp/cakephp/security/advisories/GHSA-2qh5-382h-3jpc
- nvd.nist.gov/vuln/detail/CVE-2026-77634
- github.com/cakephp/cakephp/commit/08188962bcd99a95da1e49f62e786f2d688f1e41
- github.com/cakephp/cakephp/commit/2afe42b02d8ddc5d442bca5e8bb61910a727646e
- github.com/cakephp/cakephp/commit/3e09dae6cbdc983754fa3a8e6aae74da102a3ea1
- github.com/cakephp/cakephp/commit/b67b622457362b075bb37e625a82af73a0b3c9c3
- github.com/cakephp/cakephp