How severe is CVE-2021-29950?

CVE-2021-29950 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-29950 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-29950?

CVE-2021-29950 affects Mozilla Thunderbird. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-29950?

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-2021-29950 published?

CVE-2021-29950 was published on 2021-06-24 and last updated on 2026-06-17.

CVE-2021-29950

CVE-2021-29950 is a high-severity vulnerability in Mozilla Thunderbird with a CVSS 3.x base score of 7.5. 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-312.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (54th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-312
Affected product: Mozilla Thunderbird
Published: 2021-06-24
Last modified: 2026-06-17

Description

Thunderbird unprotects a secret OpenPGP key prior to using it for a decryption, signing or key import task. If the task runs into a failure, the secret key may remain in memory in its unprotected state. This vulnerability affects Thunderbird < 78.8.1.

Frequently asked questions

What is CVE-2021-29950?: Thunderbird unprotects a secret OpenPGP key prior to using it for a decryption, signing or key import task. If the task runs into a failure, the secret key may remain in memory in its unprotected state. This vulnerability affects Thunderbird < 78.8.1.
How severe is CVE-2021-29950?: CVE-2021-29950 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-29950 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-29950?: CVE-2021-29950 affects Mozilla Thunderbird. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-29950?: 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-2021-29950 published?: CVE-2021-29950 was published on 2021-06-24 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

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