How severe is CVE-2021-29495?

CVE-2021-29495 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2021-29495 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-29495?

CVE-2021-29495 affects Nim-lang Nim. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-29495?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-29495 published?

CVE-2021-29495 was published on 2021-05-07 and last updated on 2026-06-17.

CVE-2021-29495

CVE-2021-29495 is a medium-severity vulnerability in Nim-lang Nim with a CVSS 3.x base score of 5.9. 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-295.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 5.0
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Nim-lang Nim
Published: 2021-05-07
Last modified: 2026-06-17

Description

Nim is a statically typed compiled systems programming language. In Nim standard library before 1.4.2, httpClient SSL/TLS certificate verification was disabled by default. Users can upgrade to version 1.4.2 to receive a patch or, as a workaround, set "verifyMode = CVerifyPeer" as documented.

Frequently asked questions

What is CVE-2021-29495?: Nim is a statically typed compiled systems programming language. In Nim standard library before 1.4.2, httpClient SSL/TLS certificate verification was disabled by default. Users can upgrade to version 1.4.2 to receive a patch or, as a workaround, set "verifyMode = CVerifyPeer" as documented.
How severe is CVE-2021-29495?: CVE-2021-29495 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2021-29495 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-29495?: CVE-2021-29495 affects Nim-lang Nim. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-29495?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-29495 published?: CVE-2021-29495 was published on 2021-05-07 and last updated on 2026-06-17.

References

https://github.com/nim-lang/security/security/advisories/GHSA-9vqv-2jj9-7mqr

Affected products (1)

cpe:2.3:a:nim-lang:nim:*:*:*:*:*:*:*:*

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