CVE-2026-4873
Low
No strong exploitation signal.
CVSS base
5.9
MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS — probability of exploitation (30 days)
0.3%
26.2th percentile
CISA KEV
Not listed
Weakness / dates
CWE-319
Published 2026-05-13 · modified 2026-09-15
CVSS breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
| Attack Vector | N | Network |
| Attack Complexity | H | High |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | N | None |
| Availability | N | None |
Timeline
- 2026-05-13 — Published (NVD)
- 2026-09-15 — Last modified (NVD)
Description
A vulnerability exists where a connection requiring TLS incorrectly reuses an existing unencrypted connection from the same connection pool. If an initial transfer is made in clear-text (via IMAP, SMTP, or POP3), a subsequent request to that same host bypasses the TLS requirement and instead transmit data unencrypted.