CVE-2026-18393: Memory Corruption (CVSS 5.4)

Description

A flaw was found in FFmpeg. The tdsc_load_cursor() function writes beyond the bounds of a heap-allocated buffer when processing crafted TDSC cursor data. A remote attacker could exploit this by supplying a specially crafted video file, potentially leading to a denial of service or arbitrary code execution.

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CVSS v3.1 Score

5.4

MEDIUM

CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:H

EPSS — Exploit Prediction

0.0026

Probability of exploitation

0.17%

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-787 Out-of-bounds Write

References

Other References

https://access.redhat.com/security/cve/CVE-2026-18393 https://bugzilla.redhat.com/show_bug.cgi?id=2520309 https://github.com/FFmpeg/FFmpeg/commit/242ff799c75f20bade946314c8d741d0887ee11c https://patchwork.ffmpeg.org/project/ffmpeg/patch/177767065817.63.1948165304485903849@29965ddac10e/

Frequently Asked Questions

What is CVE-2026-18393? +

A flaw was found in FFmpeg. The tdsc_load_cursor() function writes beyond the bounds of a heap-allocated buffer when processing crafted TDSC cursor data. A remote attacker could exploit this by supplying a specially crafted video file, potentially leading to a denial of service or arbitrary code execution. It has a CVSS v3.1 base score of 5.4 (MEDIUM).

How severe is CVE-2026-18393? +

CVE-2026-18393 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0026, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-18393? +

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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