CVE-2026-32945
Heap-Based Buffer Overflow in PJSIP DNS Parser
Publication date: 2026-03-20
Last updated on: 2026-03-23
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| pjsip | pjsip | to 2.17 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-122 | A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
[{'type': 'paragraph', 'content': 'CVE-2026-32945 is a high-severity heap-based buffer overflow vulnerability found in the DNS parser of the PJSIP multimedia communication library, specifically in the name length handler.'}, {'type': 'paragraph', 'content': 'This vulnerability affects PJSIP versions 2.16 and below and occurs when the built-in DNS resolver processes DNS name pointers without proper boundary checks, potentially leading to out-of-bounds memory access.'}, {'type': 'paragraph', 'content': "Applications using PJSIP's built-in DNS resolver configured via pjsua_config.nameserver or UaConfig.nameserver are impacted, while those relying on the OS resolver or an external resolver are not affected."}, {'type': 'paragraph', 'content': 'The issue was fixed in version 2.17 by adding boundary checks to prevent reading beyond the buffer limits during DNS name parsing.'}] [1, 2]
How can this vulnerability impact me? :
[{'type': 'paragraph', 'content': 'This heap-based buffer overflow vulnerability can lead to memory corruption when processing DNS responses, which may cause application crashes or potentially allow an attacker to execute arbitrary code.'}, {'type': 'paragraph', 'content': "If your application uses PJSIP's built-in DNS resolver, it could be exploited by specially crafted DNS packets to compromise the stability or security of your system."}, {'type': 'paragraph', 'content': 'Users who do not configure a nameserver in PJSIP or use an external DNS resolver are not impacted by this vulnerability.'}] [1]
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
[{'type': 'paragraph', 'content': "This vulnerability was identified by the fuzz-dns-records fuzzer targeting the DNS parser in PJSIP. Detection involves monitoring or testing applications using PJSIP's built-in DNS resolver configured via pjsua_config.nameserver or UaConfig.nameserver."}, {'type': 'paragraph', 'content': "Since the issue is a heap-based buffer overflow in the DNS parser's name length handler, detection could involve fuzz testing DNS responses or analyzing application crashes related to DNS resolution."}, {'type': 'paragraph', 'content': 'No specific detection commands are provided in the available resources.'}] [1]
What immediate steps should I take to mitigate this vulnerability?
The vulnerability is fixed in PJSIP version 2.17. The primary mitigation step is to upgrade to version 2.17 or later.
If upgrading is not possible immediately, you can mitigate the issue by disabling DNS resolution in the PJSIP configuration by setting nameserver_count to zero.
Alternatively, configure PJSIP to use an external DNS resolver implementation instead of the built-in DNS resolver, for example by using pjsip_resolver_set_ext_resolver().