strongMan vulnerable to private credential recovery due to key and counter reuse

published 2026-02-19 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-8439

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 28%
public exploits: 0; none known

strongMan is a management interface for strongSwan, an OpenSource IPsec-based VPN. When storing credentials in the database (private keys, EAP secrets), strongMan encrypts the corresponding database fields. So far it used AES in CTR mode with a global database key. Together with an initialization vector (IV), a key stream is generated to encrypt the data in the database fields. But because strongMan did not generate individual IVs, every database field was encrypted using the same key stream. An attacker that has access to the database can use this to recover the encrypted credentials. In particular, because certificates, which have to be considered public information, are also encrypted using the same mechanism, an attacker can directly recover a large chunk of the key stream, which allows them to decrypt basically all other secrets especially ECDSA private keys and EAP secrets, which are usually a lot shorter. Version 0.2.0 fixes the issue by switching to AES-GCM-SIV encryption with a random nonce and an individually derived encryption key, using HKDF, for each encrypted value. Database migrations are provided to automatically re-encrypt all credentials.

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 8 mo ago (2026-02-20)

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.7	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CNA	4.0	8.7	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

strongswan strongMan

Classification

Weakness

CWE-323 Reusing a Nonce, Key Pair in Encryption
CWE-1204 Generation of Weak Initialization Vector (IV)

References

github.com /strongswan/strongMan/security/advisories/GHSA-88w4-jv97-c8xr
vendor-advisory

Sources

CVE List CVE-2026-25998
NVD CVE-2026-25998

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Summary