What is CVE-2023-26991?

CVE-2023-26991 is a high-severity vulnerability in Swftools, classified under Use After Free. CVSS score: 7.8/10. Published 2023-04-04.

How severe is CVE-2023-26991?

High severity. CVSS v3 base score is 7.8 out of 10.

Use After Free in Swftools

CVE-2023-26991

SWFTools v0.9.2 was discovered to contain a stack-use-after-scope in the swf_ReadSWF2 function in lib/rfxswf.c.

Vulnerability class: Use-After-Free

Published 2023-04-04 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (21.9th percentile), scored 2026-10-07.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 22nd percentile — 21.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Swftools — versions 0.9.2

Weakness classification (CWE)

CWE-416 — Use After Free

References

github.com/matthiaskramm/swftools/issues/196 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2023-26991?: CVE-2023-26991 is a high-severity vulnerability in Swftools, classified under Use After Free. CVSS score: 7.8/10. Published 2023-04-04.
How severe is CVE-2023-26991?: High severity. CVSS v3 base score is 7.8 out of 10.