How severe is CVE-2021-27799?

CVE-2021-27799 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-27799 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27799?

CVE-2021-27799 affects Zint Barcode Generator. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27799?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-27799 published?

CVE-2021-27799 was published on 2021-02-26 and last updated on 2026-06-17.

CVE-2021-27799

CVE-2021-27799 is a high-severity vulnerability in Zint Barcode Generator with a CVSS 3.x base score of 7.5. 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-787.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Zint Barcode Generator
Published: 2021-02-26
Last modified: 2026-06-17

Description

ean_leading_zeroes in backend/upcean.c in Zint Barcode Generator 2.9.1 has a stack-based buffer overflow that is reachable from the C API through an application that includes the Zint Barcode Generator library code.

Frequently asked questions

What is CVE-2021-27799?: ean_leading_zeroes in backend/upcean.c in Zint Barcode Generator 2.9.1 has a stack-based buffer overflow that is reachable from the C API through an application that includes the Zint Barcode Generator library code.
How severe is CVE-2021-27799?: CVE-2021-27799 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-27799 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27799?: CVE-2021-27799 affects Zint Barcode Generator. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27799?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-27799 published?: CVE-2021-27799 was published on 2021-02-26 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:zint:barcode_generator:2.9.1:*:*:*:*:*:*:*

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