How severe is CVE-2021-44549?

CVE-2021-44549 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-44549 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-2021-44549?

CVE-2021-44549 affects Apache Sling Commons Messaging Mail. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-44549?

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-2021-44549 published?

CVE-2021-44549 was published on 2021-12-14 and last updated on 2026-06-17.

CVE-2021-44549

CVE-2021-44549 is a high-severity vulnerability in Apache Sling Commons Messaging Mail with a CVSS 3.x base score of 7.4. 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: High (CVSS 3.x base score 7.4)
CVSS v2: 5.8
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Apache Sling Commons Messaging Mail
Published: 2021-12-14
Last modified: 2026-06-17

Description

Apache Sling Commons Messaging Mail provides a simple layer on top of JavaMail/Jakarta Mail for OSGi to send mails via SMTPS. To reduce the risk of "man in the middle" attacks additional server identity checks must be performed when accessing mail servers. For compatibility reasons these additional checks are disabled by default in JavaMail/Jakarta Mail. The SimpleMailService in Apache Sling Commons Messaging Mail 1.0 lacks an option to enable these checks for the shared mail session. A user could enable these checks nevertheless by accessing the session via the message created by SimpleMessageBuilder and setting the property mail.smtps.ssl.checkserveridentity to true. Apache Sling Commons Messaging Mail 2.0 adds support for enabling server identity checks and these checks are enabled by default. - https://javaee.github.io/javamail/docs/SSLNOTES.txt - https://javaee.github.io/javamail/docs/api/com/sun/mail/smtp/package-summary.html - https://github.com/eclipse-ee4j/mail/issues/429

Frequently asked questions

What is CVE-2021-44549?: Apache Sling Commons Messaging Mail provides a simple layer on top of JavaMail/Jakarta Mail for OSGi to send mails via SMTPS. To reduce the risk of "man in the middle" attacks additional server identity checks must be performed when accessing mail servers. For compatibility reasons these additional checks are disabled by default in JavaMail/Jakarta Mail. The SimpleMailService in Apache Sling Commons Messaging Mail 1.0 lacks an option to enable these checks for the shared mail session. A user could enable these checks nevertheless by accessing the session via the message created by SimpleMessageBuilder and setting the property mail.smtps.ssl.checkserveridentity to true. Apache Sling Commons Messaging Mail 2.0 adds support for enabling server identity checks and these checks are enabled by default. - https://javaee.github.io/javamail/docs/SSLNOTES.txt - https://javaee.github.io/javamail/docs/api/com/sun/mail/smtp/package-summary.html - https://github.com/eclipse-ee4j/mail/issues/429
How severe is CVE-2021-44549?: CVE-2021-44549 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-44549 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-2021-44549?: CVE-2021-44549 affects Apache Sling Commons Messaging Mail. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-44549?: 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-2021-44549 published?: CVE-2021-44549 was published on 2021-12-14 and last updated on 2026-06-17.

References

https://lists.apache.org/thread/l8p9h2bqvkj6rhv4w8kzctb817415b7f

Affected products (1)

cpe:2.3:a:apache:sling_commons_messaging_mail:1.0.0:*:*:*:*:*:*:*

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