How severe is CVE-2021-45693?

CVE-2021-45693 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-45693 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-2021-45693?

CVE-2021-45693 affects Messagepack-rs Project Messagepack-rs. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-45693?

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

When was CVE-2021-45693 published?

CVE-2021-45693 was published on 2021-12-27 and last updated on 2026-06-17.

CVE-2021-45693

CVE-2021-45693 is a critical-severity vulnerability in Messagepack-rs Project Messagepack-rs with a CVSS 3.x base score of 9.8. 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-908.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (64th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-908
Affected product: Messagepack-rs Project Messagepack-rs
Published: 2021-12-27
Last modified: 2026-06-17

Description

An issue was discovered in the messagepack-rs crate through 2021-01-26 for Rust. deserialize_string_primitive may read from uninitialized memory locations.

Frequently asked questions

What is CVE-2021-45693?: An issue was discovered in the messagepack-rs crate through 2021-01-26 for Rust. deserialize_string_primitive may read from uninitialized memory locations.
How severe is CVE-2021-45693?: CVE-2021-45693 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-45693 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-2021-45693?: CVE-2021-45693 affects Messagepack-rs Project Messagepack-rs. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-45693?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-45693 published?: CVE-2021-45693 was published on 2021-12-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:messagepack-rs_project:messagepack-rs:*:*:*:*:*:rust:*:*

More vulnerabilities in Messagepack-rs Project Messagepack-rs

CVE-2021-45692 — Critical (CVSS 9.8): An issue was discovered in the messagepack-rs crate through 2021-01-26 for Rust. deserialize_extension_others may read…
CVE-2021-45691 — Critical (CVSS 9.8): An issue was discovered in the messagepack-rs crate through 2021-01-26 for Rust. deserialize_string may read from…
CVE-2021-45690 — Critical (CVSS 9.8): An issue was discovered in the messagepack-rs crate through 2021-01-26 for Rust. deserialize_binary may read from…

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Other CWE-908 (Use of Uninitialized Resource) vulnerabilities

CVE-2025-1942 — Critical (CVSS 9.8): When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated…
CVE-2024-47540 — Critical (CVSS 9.8): GStreamer is a library for constructing graphs of media-handling components. An uninitialized stack variable…
CVE-2024-32611 — Critical (CVSS 9.8): HDF5 Library through 1.14.3 may use an uninitialized value in H5A__attr_release_table in H5Aint.c.
CVE-2023-24941 — Critical (CVSS 9.8): Windows Network File System Remote Code Execution Vulnerability
CVE-2022-26437 — Critical (CVSS 9.8): In httpclient, there is a possible out of bounds write due to uninitialized data. This could lead to remote escalation…
CVE-2021-45703 — Critical (CVSS 9.8): An issue was discovered in the tectonic_xdv crate before 0.1.12 for Rust. XdvParser::<T>::process may read from…

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