CVE-2026-128089
dnspython excessive memory and CPU use
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
dnspython is a DNS toolkit for Python. Prior to version 2.9.2, the from_text() parser for WKS records does not require the service number to be between 0 and 65535 before using it as a bitmap offset. An attacker-controlled zone file can supply a larger number, causing the service bitmap to grow to an extremely large size through inefficient repeated extension, consuming excessive memory and CPU and potentially terminating the process. Applications are affected only when they parse zone-file text whose record type and rdata are attacker controlled. This issue is fixed in version 2.9.2.
| CWE | CWE-400 CWE-770 |
| Vendor | rthalley |
| Product | dnspython |
| Published | Nov 13, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
rthalley / dnspython
< 2.9.2
References
github.com: https://github.com/rthalley/dnspython/security/advisories/GHSA-vvf4-9x63-8xvv github.com: https://github.com/rthalley/dnspython/commit/388db14ee9923288f6e73f86e482c77706e59d73 github.com: https://github.com/rthalley/dnspython/commit/a62e1be066da0ed71b5b59f37435bb17cfa0070f github.com: https://github.com/rthalley/dnspython/releases/tag/v2.9.2