CVE-2026-48840

MEDIUM
Published May 30, 2026 Modified Jun 3, 2026 CWE-839

Description

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.

CVSS v3.1 Score

5.3
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS — Exploit Prediction

0.0027
Probability of exploitation
0.19%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-839 CWE-839

Affected Products

Vendor Product
exim exim

References

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 5.3 (MEDIUM).
How severe is CVE-2026-48840? +
CVE-2026-48840 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0027, placing it in the 0th percentile for exploitation probability.
What products are affected by CVE-2026-48840? +
CVE-2026-48840 affects products from exim, specifically: exim. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2026-48840? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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