How severe is CVE-2021-33196?

CVE-2021-33196 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-2021-33196 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33196?

CVE-2021-33196 primarily affects Golang Go. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-33196?

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-2021-33196 published?

CVE-2021-33196 was published on 2021-08-02 and last updated on 2026-06-17.

CVE-2021-33196

CVE-2021-33196 is a high-severity vulnerability in Golang Go 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-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 3% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Golang Go
Published: 2021-08-02
Last modified: 2026-06-17

Description

In archive/zip in Go before 1.15.13 and 1.16.x before 1.16.5, a crafted file count (in an archive's header) can cause a NewReader or OpenReader panic.

Frequently asked questions

What is CVE-2021-33196?: In archive/zip in Go before 1.15.13 and 1.16.x before 1.16.5, a crafted file count (in an archive's header) can cause a NewReader or OpenReader panic.
How severe is CVE-2021-33196?: CVE-2021-33196 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-2021-33196 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33196?: CVE-2021-33196 primarily affects Golang Go. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-33196?: 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-2021-33196 published?: CVE-2021-33196 was published on 2021-08-02 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

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