7.3

CVE-2026-78135: strongswan

CVSS: 7.3v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-78135DEBIAN-CVE-2026-78135
Published 11-09-2026Last modified 15-09-2026
Open JSON

Vulnerability summary

CVE-2026-78135 is a high (CVSS 7.3) vulnerability in strongswan. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28.6% of scored vulnerabilities.

Overall risk
29/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.3/10
010
High · v3.1 (NVD)
EPSS score
0.36%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 5 · Related 5
OPENSUSE-SU-2026:11749-1OPENSUSE-SU-2026:22050-1SUSE-SU-2026:4115-1SUSE-SU-2026:4146-1USN-8789-1

Timeline

  1. 11-09-2026
    PublishedVulnerability first disclosed.
  2. 15-09-2026
    Last modifiedVulnerability information updated.

Description

libcharon in strongSwan 5.9.7 through 6.0.7 mishandles behavioral workflow in the IKEv2 state machine. Because CREATE_CHILD_SA requests are mishandled, there can be an authentication bypass.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.36%

Chance of exploitation in the next 30 days

Percentile

29%

Versus all other CVEs

30-day change

0.00 pp

From 0.36% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.36%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • strongswanAll versions (No fix recorded) | < 6.0.1-6+deb13u7 | < 6.1.0-1
Strongswan1 product
  • strongswan≥ 5.9.7, < 6.1.0 | ≥ 5.9.7, ≤ 6.0.7
Ubuntu1 product
  • strongswanAll versions (No fix recorded) | < 5.9.5-2ubuntu2.8 | < 5.9.13-2ubuntu4.24.04.5 | < 6.0.4-1ubuntu3.2

3 vendors · 3 products

References

7 links