How severe is CVE-2021-4156?

CVE-2021-4156 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability high.

Is CVE-2021-4156 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-4156?

CVE-2021-4156 primarily affects Libsndfile Project Libsndfile. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-4156?

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-2021-4156 published?

CVE-2021-4156 was published on 2022-03-23 and last updated on 2026-06-17.

CVE-2021-4156

CVE-2021-4156 is a high-severity vulnerability in Libsndfile Project Libsndfile with a CVSS 3.x base score of 7.1. 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: High (CVSS 3.x base score 7.1)
CVSS v2: 5.8
EPSS exploit prediction: 2% (75th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Libsndfile Project Libsndfile
Published: 2022-03-23
Last modified: 2026-06-17

Description

An out-of-bounds read flaw was found in libsndfile's FLAC codec functionality. An attacker who is able to submit a specially crafted file (via tricking a user to open or otherwise) to an application linked with libsndfile and using the FLAC codec, could trigger an out-of-bounds read that would most likely cause a crash but could potentially leak memory information that could be used in further exploitation of other flaws.

Frequently asked questions

What is CVE-2021-4156?: An out-of-bounds read flaw was found in libsndfile's FLAC codec functionality. An attacker who is able to submit a specially crafted file (via tricking a user to open or otherwise) to an application linked with libsndfile and using the FLAC codec, could trigger an out-of-bounds read that would most likely cause a crash but could potentially leak memory information that could be used in further exploitation of other flaws.
How severe is CVE-2021-4156?: CVE-2021-4156 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability high.
Is CVE-2021-4156 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-4156?: CVE-2021-4156 primarily affects Libsndfile Project Libsndfile. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-4156?: 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-2021-4156 published?: CVE-2021-4156 was published on 2022-03-23 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:libsndfile_project:libsndfile:1.1.10:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

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