PatchTheCVECVE-2021-39247: Zint Barcode Generator before 2.10.0 has a one-byte buffer over-read, related to is_last_single_ascii in code1
CVE-2021-39247 is a medium-severity flaw (CVSS 6.5) affecting barcode generator. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- Public exploit reference
A fixed release or distro patch exists.
Risk facts
| CVSS score | 6.5 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | Required |
| EPSS exploit chance | 0.9% (top 40%) |
| CISA exploited list | No |
| Weakness | CWE-125 |
| Published | 2021-08-17 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2021-39247?
barcode generator: upgrade to 2.10.0. Exact commands for each OS are on this page.
Is CVE-2021-39247 being exploited?
CVE-2021-39247 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2021-39247 affect?
CVE-2021-39247 affects barcode generator. Severity is medium (CVSS 6.5). 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.
How urgent is CVE-2021-39247?
Priority 43/100. Public exploit reference
Related CVEs
- CVE-2021-27799 HIGH 7.5 DOWNGRADE ean_leading_zeroes in backend/upcean.c in Zint Barcode Generator 2.9.1 has a stack-based buffer overflow that