What is CVE-2026-48840?

CVE-2026-48840 is a medium-severity vulnerability in Exim, classified under CWE-839. CVSS score: 5.3/10. Published 2026-05-30.

How severe is CVE-2026-48840?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Exim

CVE-2026-48840

Exim 4.88 before 4.99.4, in some proxy configurations, mishandles certain short payloads, leading to disclosure of uninitialized stack memory values to a client.

EPSS: 0.000 (9.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Exim — versions 4.88

Weakness classification (CWE)

CWE-839

References

cve@mitre.org (Vendor Advisory)
cve@mitre.org (Mailing List, Third Party Advisory, Mitigation)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory, Mitigation)
af854a3a-2127-422b-91ae-364da2661108

Frequently asked questions

What is CVE-2026-48840?: CVE-2026-48840 is a medium-severity vulnerability in Exim, classified under CWE-839. CVSS score: 5.3/10. Published 2026-05-30.
How severe is CVE-2026-48840?: Medium severity. CVSS v3 base score is 5.3 out of 10.