What is CVE-2021-39247?

CVE-2021-39247 is a medium-severity vulnerability in Zint Barcode Generator, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2021-08-17.

How severe is CVE-2021-39247?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Out-of-bounds Read in Zint Barcode Generator

CVE-2021-39247

Zint Barcode Generator before 2.10.0 has a one-byte buffer over-read, related to is_last_single_ascii in code1.c, and rs_encode_uint in reedsol.c.

Vulnerability class: Buffer Overflow

Published 2021-08-17 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.009 (59.1th percentile), scored 2026-10-07.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 59.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Zint Barcode Generator

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

sourceforge.net/p/zint/tickets/232/ (Exploit, Patch, Third Party Advisory, Issue Tracking)
sourceforge.net/p/zint/code/ci/9b02cd52214e80f945bff41fc94bc1e17e15810c/ (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-39247?: CVE-2021-39247 is a medium-severity vulnerability in Zint Barcode Generator, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2021-08-17.
How severe is CVE-2021-39247?: Medium severity. CVSS v3 base score is 6.5 out of 10.