How severe is CVE-2016-7966?

CVE-2016-7966 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2016-7966 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-7966?

CVE-2016-7966 primarily affects Kde Kmail. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-7966?

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-2016-7966 published?

CVE-2016-7966 was published on 2016-12-23 and last updated on 2026-06-17.

CVE-2016-7966

CVE-2016-7966 is a high-severity vulnerability in Kde Kmail with a CVSS 3.x base score of 7.3. 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-94.

Key facts

Severity: High (CVSS 3.x base score 7.3)
CVSS v2: 7.5
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-94
Affected product: Kde Kmail
Published: 2016-12-23
Last modified: 2026-06-17

Description

Through a malicious URL that contained a quote character it was possible to inject HTML code in KMail's plaintext viewer. Due to the parser used on the URL it was not possible to include the equal sign (=) or a space into the injected HTML, which greatly reduces the available HTML functionality. Although it is possible to include an HTML comment indicator to hide content.

Frequently asked questions

What is CVE-2016-7966?: Through a malicious URL that contained a quote character it was possible to inject HTML code in KMail's plaintext viewer. Due to the parser used on the URL it was not possible to include the equal sign (=) or a space into the injected HTML, which greatly reduces the available HTML functionality. Although it is possible to include an HTML comment indicator to hide content.
How severe is CVE-2016-7966?: CVE-2016-7966 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2016-7966 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-7966?: CVE-2016-7966 primarily affects Kde Kmail. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-7966?: 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-2016-7966 published?: CVE-2016-7966 was published on 2016-12-23 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:kde:kmail:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:25:*:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise:12.0:*:*:*:*:*:*:*

More vulnerabilities in Kde Kmail

CVE-2016-7967 — High (CVSS 8.1): KMail since version 5.3.0 used a QWebEngine based viewer that had JavaScript enabled. Since the generated html is…
CVE-2017-9604 — High (CVSS 7.5): KDE kmail before 5.5.2 and messagelib before 5.5.2, as distributed in KDE Applications before 17.04.2, do not ensure…
CVE-2020-15954 — Medium (CVSS 6.5): KDE KMail 19.12.3 (aka 5.13.3) engages in unencrypted POP3 communication during times when the UI indicates that…
CVE-2020-11880 — Medium (CVSS 6.5): An issue was discovered in KDE KMail before 19.12.3. By using the proprietary (non-RFC6068) "mailto?attach=..."…
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CVE-2017-17689 — Medium (CVSS 5.9): The S/MIME specification allows a Cipher Block Chaining (CBC) malleability-gadget attack that can indirectly lead to…

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