How severe is CVE-2018-16868?

CVE-2018-16868 has a CVSS 3.x base score of 5.6, rated medium severity. It is exploitable over physical access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.

Is CVE-2018-16868 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-16868?

CVE-2018-16868 affects Gnu Gnutls. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-16868?

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

When was CVE-2018-16868 published?

CVE-2018-16868 was published on 2018-12-03 and last updated on 2026-06-17.

CVE-2018-16868

CVE-2018-16868 is a medium-severity vulnerability in Gnu Gnutls with a CVSS 3.x base score of 5.6. 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-203.

Key facts

Severity: Medium (CVSS 3.x base score 5.6)
CVSS v2: 3.3
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-203
Affected product: Gnu Gnutls
Published: 2018-12-03
Last modified: 2026-06-17

Description

A Bleichenbacher type side-channel based padding oracle attack was found in the way gnutls handles verification of RSA decrypted PKCS#1 v1.5 data. An attacker who is able to run process on the same physical core as the victim process, could use this to extract plaintext or in some cases downgrade any TLS connections to a vulnerable server.

Frequently asked questions

What is CVE-2018-16868?: A Bleichenbacher type side-channel based padding oracle attack was found in the way gnutls handles verification of RSA decrypted PKCS#1 v1.5 data. An attacker who is able to run process on the same physical core as the victim process, could use this to extract plaintext or in some cases downgrade any TLS connections to a vulnerable server.
How severe is CVE-2018-16868?: CVE-2018-16868 has a CVSS 3.x base score of 5.6, rated medium severity. It is exploitable over physical access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.
Is CVE-2018-16868 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-16868?: CVE-2018-16868 affects Gnu Gnutls. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-16868?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-16868 published?: CVE-2018-16868 was published on 2018-12-03 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:gnu:gnutls:*:*:*:*:*:*:*:*

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