# DLA-4359-1: strongswan security update

DLA-4359-1, released November 3, 2025, fixes 1 CVE in strongswan (version 5.9.1-1+deb11u5). None of them is reported as exploited. Patch Radar priority: High. The product is no longer supported.

- Web page: https://patchblox.com/security/fix/linux/dla-4359-1
- Platform: Linux
- Released: Nov 3, 2025
- Priority: High (Closes CVE-2025-62291, high severity)
- CVEs: 1, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://security-tracker.debian.org/tracker/CVE-2025-62291

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [strongswan](https://patchblox.com/security/data/product/linux/strongswan.md) | Debian 11.6 (bullseye) | 5.9.1-1+deb11u5 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2025-62291](https://patchblox.com/security/data/cve/CVE-2025-62291.md) | High | In the eap-mschapv2 plugin (client-side) in strongSwan before 6.0.3, a malicious EAP-MSCHAPv2 server can send a crafted message of size 6 through 8, and cause an integer underflow that potentially results in a heap-based buffer overflow. | 8.1 | 0.0098 |  |

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Data as of 2026-11-07T06:34:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo