How severe is CVE-2021-40439?

CVE-2021-40439 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-40439 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-40439?

CVE-2021-40439 affects Apache Openoffice. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-40439?

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

When was CVE-2021-40439 published?

CVE-2021-40439 was published on 2021-10-07 and last updated on 2026-06-17.

CVE-2021-40439

CVE-2021-40439 is a medium-severity vulnerability in Apache Openoffice with a CVSS 3.x base score of 6.5. 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-611.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 3% (87th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-611
Affected product: Apache Openoffice
Published: 2021-10-07
Last modified: 2026-06-17

Description

Apache OpenOffice has a dependency on expat software. Versions prior to 2.1.0 were subject to CVE-2013-0340 a "Billion Laughs" entity expansion denial of service attack and exploit via crafted XML files. ODF files consist of a set of XML files. All versions of Apache OpenOffice up to 4.1.10 are subject to this issue. expat in version 4.1.11 is patched.

Frequently asked questions

What is CVE-2021-40439?: Apache OpenOffice has a dependency on expat software. Versions prior to 2.1.0 were subject to CVE-2013-0340 a "Billion Laughs" entity expansion denial of service attack and exploit via crafted XML files. ODF files consist of a set of XML files. All versions of Apache OpenOffice up to 4.1.10 are subject to this issue. expat in version 4.1.11 is patched.
How severe is CVE-2021-40439?: CVE-2021-40439 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-40439 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-40439?: CVE-2021-40439 affects Apache Openoffice. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-40439?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-40439 published?: CVE-2021-40439 was published on 2021-10-07 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:apache:openoffice:*:*:*:*:*:*:*:*

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