No exploitation reportedFix available

CVE-2018-1000808

Q: Is CVE-2018-1000808 actively exploited?

Active exploitation of CVE-2018-1000808 has not been confirmed. Its EPSS score was 1.9% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2018-1000808?

CVE-2018-1000808 has a CVSS v3 base score of 5.9 (MEDIUM severity), with vector string CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

No exploitation reported by the sources we read.

Published2018-10-08
WeaknessCWE-404

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Python Cryptographic Authority pyopenssl version Before 17.5.0 contains a CWE - 401 : Failure to Release Memory Before Removing Last Reference vulnerability in PKCS #12 Store that can result in Denial of service if memory runs low or is exhausted. This attack appear to be exploitable via Depends upon calling application, however it could be as simple as initiating a TLS connection. Anything that would cause the calling application to reload certificates from a PKCS #12 store.. This vulnerability appears to have been fixed in 17.5.0.

Timeline

dates in UTC

2018-10-0815:29CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2018-1000808?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-1000808?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV

Canonical ubuntu linux

Branch	Affected	Fixed in	Source
16.4	= 16.04	no fix published	NVD

Pyopenssl project pyopenssl

Branch	Affected	Fixed in	Source
17.5	< 17.5.0	17.5.0	NVD · OSV

Redhat enterprise linux desktop

Branch	Affected	Fixed in	Source
7.0	= 7.0	no fix published	NVD

4 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

github.comPatch

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.05.9read 2026-10-23
NVDCVSS 2.04.3read 2026-10-23
NVDweakness (CWE)CWE-404read 2026-10-23
FIRST EPSSEPSS score1.9 %2026-10-23
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2018-10-08
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2018-1000808?

Is CVE-2018-1000808 actively exploited?

Active exploitation of CVE-2018-1000808 has not been confirmed. Its EPSS score was 1.9% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2018-1000808?

CVE-2018-1000808 has a CVSS v3 base score of 5.9 (MEDIUM severity), with vector string CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

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