What is CVE-2026-123199?

CVE-2026-123199 is a medium-severity vulnerability in Book-Readers Ebook-Speaker, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 5.5/10. Published 2026-11-05.

How severe is CVE-2026-123199?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Buffer overflow in Book-Readers Ebook-Speaker

CVE-2026-123199

eBook-speaker 6.1.0 through 6.2.0 contains a stack buffer overflow vulnerability in get_attributes() in src/common.c caused by an unbounded strcpy of an element's name attribute. Attackers can craft an EPUB or DAISY book with a name attribute of 511 or more characters to corrupt the stack and crash the reader when opened.

Vulnerability class: Buffer Overflow

Published 2026-11-05.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.001 (3.6th percentile), scored 2026-11-09.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 3.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Book-Readers Ebook-Speaker

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

github.com/book-readers/ebook-speaker/blob/4a8f457a0fd65a96463c0fa9bd0612242c08… (technical-description)
github.com/book-readers/ebook-speaker/commit/23b5c86585d7e3c27c932b112f4e36858e… (patch)
www.vulncheck.com/advisories/ebook-speaker-through-6.2.0-stack-based-buffer-ove… (third-party-advisory)

Frequently asked questions

What is CVE-2026-123199?: CVE-2026-123199 is a medium-severity vulnerability in Book-Readers Ebook-Speaker, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 5.5/10. Published 2026-11-05.
How severe is CVE-2026-123199?: Medium severity. CVSS v3 base score is 5.5 out of 10.