How severe is CVE-2021-3888?

CVE-2021-3888 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2021-3888 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3888?

CVE-2021-3888 affects Libmobi Project Libmobi. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-3888?

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-2021-3888 published?

CVE-2021-3888 was published on 2021-10-19 and last updated on 2026-06-17.

CVE-2021-3888

CVE-2021-3888 is a high-severity vulnerability in Libmobi Project Libmobi with a CVSS 3.x base score of 8.1. 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-119.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 5.8
EPSS exploit prediction: 1% (64th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Libmobi Project Libmobi
Published: 2021-10-19
Last modified: 2026-06-17

Description

libmobi is vulnerable to Use of Out-of-range Pointer Offset

Frequently asked questions

What is CVE-2021-3888?: libmobi is vulnerable to Use of Out-of-range Pointer Offset
How severe is CVE-2021-3888?: CVE-2021-3888 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2021-3888 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3888?: CVE-2021-3888 affects Libmobi Project Libmobi. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-3888?: 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-2021-3888 published?: CVE-2021-3888 was published on 2021-10-19 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:libmobi_project:libmobi:*:*:*:*:*:*:*:*

More vulnerabilities in Libmobi Project Libmobi

CVE-2021-3881 — Critical (CVSS 9.8): libmobi is vulnerable to Out-of-bounds Read
CVE-2021-3751 — Critical (CVSS 9.8): libmobi is vulnerable to Out-of-bounds Write
CVE-2018-11726 — High (CVSS 8.8): The mobi_decode_font_resource function in util.c in Libmobi 0.3 allows remote attackers to cause a denial of service…
CVE-2018-11724 — High (CVSS 8.8): The mobi_pk1_decrypt function in encryption.c in Libmobi 0.3 allows remote attackers to cause a denial of service…
CVE-2018-11438 — High (CVSS 8.8): The mobi_decompress_lz77 function in compression.c in Libmobi 0.3 allows remote attackers to cause remote code…
CVE-2022-1987 — High (CVSS 8.1): Buffer Over-read in GitHub repository bfabiszewski/libmobi prior to 0.11.

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