SB2026072873 - Debian update for openvpn
Published: July 28, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 6 vulnerabilities.
1) Out-of-bounds write (CVE-ID: CVE-2026-11771)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to out-of-bounds write in NTLMv2 proxy responses when parsing response data. A remote attacker can send specially crafted response data to cause a denial of service.
The advisory describes the overrun as limited to one byte.
2) Memory leak (CVE-ID: CVE-2026-12932)
CWE-ID: CWE-401 - Missing release of memory after effective lifetime
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a memory leak in tls-crypt-v2 client key handling when processing tls-crypt-v2 client keys. A remote attacker can send a sequence of crafted inputs to cause a denial of service.
The issue can lead to an out-of-memory condition before the server crashes.
3) Use-after-free (CVE-ID: CVE-2026-12996)
CWE-ID: CWE-416 - Use After Free
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to use-after-free in ack_write_buf() when processing a well-timed sequence of control channel and authentication packets. A remote attacker can send a specially crafted packet sequence to cause a denial of service.
4) Use-after-free (CVE-ID: CVE-2026-13117)
CWE-ID: CWE-416 - Use After Free
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to use-after-free in tls_wrap_reneg() when processing a suitable sequence of dynamic tls-crypt control-channel packets. A remote attacker can send a specially crafted packet sequence to cause a denial of service.
5) Input validation error (CVE-ID: CVE-2026-13122)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper input validation in auth-token handling when processing a suitably malformed auth-token. A remote attacker can send a specially crafted auth-token to cause a denial of service.
Only servers with --auth-gen-token external-auth enabled are vulnerable.
6) Memory leak (CVE-ID: CVE-2026-13698)
CWE-ID: CWE-401 - Missing release of memory after effective lifetime
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a memory leak in tls-crypt-v2 packet handling when processing suitable tls-crypt-v2 packets. A remote attacker can send specially crafted packets to cause a denial of service.
The issue can lead to an out-of-memory condition before the server crashes.
Remediation
Install update from vendor's website.