How severe is CVE-2021-24115?

CVE-2021-24115 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-2021-24115 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-24115?

CVE-2021-24115 affects Botan Project Botan. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-24115?

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-2021-24115 published?

CVE-2021-24115 was published on 2021-02-22 and last updated on 2026-06-17.

CVE-2021-24115

CVE-2021-24115 is a critical-severity vulnerability in Botan Project Botan 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.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Botan Project Botan
Published: 2021-02-22
Last modified: 2026-06-17

Description

In Botan before 2.17.3, constant-time computations are not used for certain decoding and encoding operations (base32, base58, base64, and hex).

Frequently asked questions

What is CVE-2021-24115?: In Botan before 2.17.3, constant-time computations are not used for certain decoding and encoding operations (base32, base58, base64, and hex).
How severe is CVE-2021-24115?: CVE-2021-24115 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-2021-24115 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-24115?: CVE-2021-24115 affects Botan Project Botan. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-24115?: 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-2021-24115 published?: CVE-2021-24115 was published on 2021-02-22 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:botan_project:botan:*:*:*:*:*:*:*:*

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