How severe is CVE-2021-37311?

CVE-2021-37311 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 none, integrity none, and availability high.

Is CVE-2021-37311 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-37311?

CVE-2021-37311 affects Fcitx 5 Project Fcitx 5. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-37311?

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-2021-37311 published?

CVE-2021-37311 was published on 2023-02-03 and last updated on 2026-06-17.

CVE-2021-37311

CVE-2021-37311 is a high-severity vulnerability in Fcitx 5 Project Fcitx 5 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-120.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Fcitx 5 Project Fcitx 5
Published: 2023-02-03
Last modified: 2026-06-17

Description

Buffer Overflow vulnerability in fcitx5 5.0.8 allows attackers to cause a denial of service via crafted message to the application's listening port.

Frequently asked questions

What is CVE-2021-37311?: Buffer Overflow vulnerability in fcitx5 5.0.8 allows attackers to cause a denial of service via crafted message to the application's listening port.
How severe is CVE-2021-37311?: CVE-2021-37311 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 none, integrity none, and availability high.
Is CVE-2021-37311 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-37311?: CVE-2021-37311 affects Fcitx 5 Project Fcitx 5. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-37311?: 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-2021-37311 published?: CVE-2021-37311 was published on 2023-02-03 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:fcitx_5_project:fcitx_5:5.0.8:*:*:*:*:*:*:*

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