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CVE-2015-3991

25
FAUCET Score

CVE-2015-3991 is a critical vulnerability affecting strongSwan versions 5.2.2 and 5.3.0, allowing remote attackers to cause a denial of service (daemon crash) or execute arbitrary code. With a CVSS score of 9.8, it presents a severe risk due to its network-based attack vector, low attack complexity, and high impact on confidentiality, integrity, and availability. Despite its critical severity, there is no evidence of active exploitation, publicly available exploit code, or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
5.2.2CPE matchmatch criteria
cpe:2.3:a:strongswan:strongswan:5.2.2:*:*:*:*:*:*:*
5.3.0CPE matchmatch criteria
cpe:2.3:a:strongswan:strongswan:5.3.0:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.0

9.8CRITICAL

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
5.9
CvssVersion
3.0

Exploit Intelligence

EPSS Score
4.52%
Probability of exploitation in next 30 days
EPSS Percentile
90.5%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0452 is in the 84th percentile among its peer group of 36,897 CVEs.

Social Chatter

No social media mentions found for this CVE.

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

lists.fedoraproject.org / pipermail/package-announce/2015-August/164276.html
Third Party Advisory
lists.fedoraproject.org / pipermail/package-announce/2015-August/164278.html
Third Party Advisory
bugzilla.redhat.com / show_bug.cgi
Issue TrackingThird Party Advisory
strongswan.org / blog/2015/06/01/strongswan-vulnerability-%28cve-2015-3991%29.html
securityfocus.com / bid/76861
Third Party AdvisoryVDB Entry