CVE-2026-25075
strongSwan 4.5.0 < 6.0.5 EAP-TTLS AVP Parsing Integer Underflow
Description
strongSwan versions 4.5.0 prior to 6.0.5 contain an integer underflow vulnerability in the EAP-TTLS AVP parser that allows unauthenticated remote attackers to cause a denial of service by sending crafted AVP data with invalid length fields during IKEv2 authentication. Attackers can exploit the failure to validate AVP length fields before subtraction to trigger excessive memory allocation or NULL pointer dereference, crashing the charon IKE daemon.
INFO
Published Date :
March 23, 2026, 7:16 p.m.
Last Modified :
March 27, 2026, 8:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update strongSwan to version 6.0.5 or later.
- Apply vendor-provided patches if upgrading is not possible.
- Validate AVP length fields during authentication.
Public PoC/Exploit Available at Github
CVE-2026-25075 has a 3 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-25075.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-25075 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-25075
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Python
DSA and DLA for Debian last 14 days
Python
📡 PoC auto collect from GitHub. ⚠️ Be careful Malware.
security cve exploit poc vulnerability
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-25075 vulnerability anywhere in the article.
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Hackread - Cybersecurity News, Data Breaches, AI and More
15-Year-Old strongSwan Flaw Lets Attackers Crash VPNs via Integer Underflow
A 15-year-old flaw in strongSwan’s EAP-TTLS plugin could let hackers knock VPNs offline. Research from Bishop Fox reveals how a simple math error leads to massive memory corruption and service collaps ... Read more
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Daily CyberSecurity
BIND 9 Security Alert: ISC Releases Patches for Trio of Vulnerabilities
The Internet Systems Consortium (ISC) has issued an important security advisory for BIND 9, the world’s most widely used DNS software. The update addresses three distinct vulnerabilities that could al ... Read more
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Daily CyberSecurity
High-Severity strongSwan Flaw Enables Remote VPN Gateway Crashes
A high-severity security vulnerability has been uncovered in strongSwan, the widely used open-source IPsec-based VPN solution. The flaw, tracked as CVE-2026-25075 with a CVSSv4 score of 8.7, resides i ... Read more
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Daily CyberSecurity
Zabbix API Vulnerability: High-Severity SQL Injection Threatens Network Monitoring Security
A high-severity security vulnerability has been identified in the Zabbix API, a popular open-source monitoring solution used by enterprises worldwide to track the status of network services, servers, ... Read more
The following table lists the changes that have been made to the
CVE-2026-25075 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Mar. 27, 2026
Action Type Old Value New Value Added Reference https://lists.debian.org/debian-lts-announce/2026/03/msg00016.html -
New CVE Received by [email protected]
Mar. 23, 2026
Action Type Old Value New Value Added Description strongSwan versions 4.5.0 prior to 6.0.5 contain an integer underflow vulnerability in the EAP-TTLS AVP parser that allows unauthenticated remote attackers to cause a denial of service by sending crafted AVP data with invalid length fields during IKEv2 authentication. Attackers can exploit the failure to validate AVP length fields before subtraction to trigger excessive memory allocation or NULL pointer dereference, crashing the charon IKE daemon. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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 Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-191 Added CWE CWE-476 Added Reference https://www.strongswan.org/blog/2026/03/23/strongswan-6.0.5-released.html Added Reference https://www.strongswan.org/blog/2026/03/23/strongswan-vulnerability-(cve-2026-25075).html Added Reference https://www.vulncheck.com/advisories/strongswan-eap-ttls-avp-parsing-integer-underflow