SB2026052101 - Debian update for pdns
Published: May 21, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 vulnerabilities.
1) Command injection (CVE-ID: CVE-2026-42000)
CWE-ID: CWE-77 - Command injection
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to modify backend configuration.
The vulnerability exists due to command injection in Bind backend AXFR name handling when processing an AXFR of a zone with specific contents. A remote attacker can provide a zone transfer containing names with special characters to modify backend configuration.
This issue affects AXFR operations involving the Bind backend and can cause the written configuration to become non-parsable until manual correction is performed.
2) Resource exhaustion (CVE-ID: CVE-2026-42001)
CWE-ID: CWE-400 - Resource exhaustion
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 missing sanity checks in the initial SOA query response handling when processing an ill-formed answer to an SOA query in autosecondary mode. A remote attacker can send or cause an ill-formed SOA query answer to cause a denial of service.
Exploitation requires the server to be running in autosecondary mode and to receive a notification for a not-yet-known domain.
3) Signal Handler Race Condition (CVE-ID: CVE-2026-42002)
CWE-ID: CWE-364 - Signal Handler Race Condition
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 race conditions in GSS-TSIG code when processing concurrent TKEY queries for the same key. A remote attacker can send concurrent TKEY queries for the same key to cause a denial of service.
Only deployments with gss-tsig support enabled are vulnerable.
4) Code Injection (CVE-ID: CVE-2026-42396)
CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to code injection in catalog zone label computation when processing an AXFR of a catalog zone with a member whose producer group option contains a double-quote character. A remote privileged user can provide catalog zone member data containing a double-quote character to cause a denial of service.
This issue causes the catalog zone transfer to fail.
Remediation
Install update from vendor's website.