How severe is CVE-2021-3928?

CVE-2021-3928 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-3928 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3928?

CVE-2021-3928 primarily affects Vim. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-3928?

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-2021-3928 published?

CVE-2021-3928 was published on 2021-11-05 and last updated on 2026-06-17.

CVE-2021-3928

CVE-2021-3928 is a high-severity vulnerability in Vim with a CVSS 3.x base score of 7.8. 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-457.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 4.6
EPSS exploit prediction: 1% (44th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-457
Affected product: Vim
Published: 2021-11-05
Last modified: 2026-06-17

Description

vim is vulnerable to Use of Uninitialized Variable

Frequently asked questions

What is CVE-2021-3928?: vim is vulnerable to Use of Uninitialized Variable
How severe is CVE-2021-3928?: CVE-2021-3928 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-3928 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3928?: CVE-2021-3928 primarily affects Vim. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-3928?: 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-2021-3928 published?: CVE-2021-3928 was published on 2021-11-05 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:a:vim:vim:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

More vulnerabilities in Vim

CVE-2020-20703 — Critical (CVSS 9.8): Buffer Overflow vulnerability in VIM v.8.1.2135 allows a remote attacker to execute arbitrary code via the operand…
CVE-2022-3520 — Critical (CVSS 9.8): Heap-based Buffer Overflow in GitHub repository vim/vim prior to 9.0.0765.
CVE-2022-0318 — Critical (CVSS 9.8): Heap-based Buffer Overflow in vim/vim prior to 8.2.
CVE-2017-6350 — Critical (CVSS 9.8): An integer overflow at an unserialize_uep memory allocation site would occur for vim before patch 8.0.0378, if it does…
CVE-2017-6349 — Critical (CVSS 9.8): An integer overflow at a u_read_undo memory allocation site would occur for vim before patch 8.0.0377, if it does not…
CVE-2017-5953 — Critical (CVSS 9.8): vim before patch 8.0.0322 does not properly validate values for tree length when handling a spell file, which may…

All CVEs affecting Vim →

Other CWE-457 vulnerabilities

CVE-2026-6748 — Critical (CVSS 9.8): Uninitialized memory in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 150, Firefox ESR…
CVE-2025-54874 — Critical (CVSS 9.8): OpenJPEG is an open-source JPEG 2000 codec. In OpenJPEG from 2.5.1 through 2.5.3, a call to opj_jp2_read_header may…
CVE-2025-53644 — Critical (CVSS 9.8): OpenCV is an Open Source Computer Vision Library. Versions 4.10.0 and 4.11.0 have an uninitialized pointer variable on…
CVE-2026-14405 — Critical (CVSS 9.6): Uninitialized Use in V8 in Google Chrome prior to 150.0.7871.46 allowed a remote attacker to execute arbitrary code…
CVE-2026-13825 — High (CVSS 8.8): Uninitialized Use in Dawn in Google Chrome prior to 150.0.7871.47 allowed a remote attacker to potentially exploit heap…
CVE-2025-5749 — High (CVSS 8.8): WOLFBOX Level 2 EV Charger BLE Encryption Keys Uninitialized Variable Authentication Bypass Vulnerability. This…

Browse all CWE-457 vulnerabilities →