How severe is CVE-2021-39247?

CVE-2021-39247 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-39247 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-39247?

CVE-2021-39247 affects Zint Barcode Generator. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-39247?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-39247 published?

CVE-2021-39247 was published on 2021-08-17 and last updated on 2026-06-17.

CVE-2021-39247

CVE-2021-39247 is a medium-severity vulnerability in Zint Barcode Generator with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Zint Barcode Generator
Published: 2021-08-17
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2021-39247?: CVE-2021-39247 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-39247 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-39247?: CVE-2021-39247 affects Zint Barcode Generator. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-39247?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-39247 published?: CVE-2021-39247 was published on 2021-08-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:zint:barcode_generator:*:*:*:*:*:*:*:*

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