Kamailio: Improper Restriction of Operations within the Bounds of a Memory Buffer
CVE-2026-93962 is a high-severity improper restriction of operations within the bounds of a memory buffer vulnerability in Kamailio, with a CVSS 3.1 base score of 8.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Kamailio versions: 5.8.0; 5.8.1; 5.8.2, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.69% chance of exploitation within 30 days, higher than 53% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Kamailio you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Kamailio | Kamailio | 5.8.0; 5.8.1; 5.8.2; 5.8.3; 5.8.4; 5.8.5; 5.8.6; 5.8.7; and 15 more ranges | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L. Scored by CNA (vuldb.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 5.5 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 8.3 | High | CNA (vuldb.com) |
| CVSS 2.0 | 7.5 | High | CNA (vuldb.com) |
Official description
A weakness has been identified in Kamailio up to 5.8.8/6.0.7/6.1.4/6.2.0-dev1. The impacted element is the function shm_malloc of the file src/modules/cdp/receiver.c of the component CDP Diameter Receiver. Executing a manipulation can lead to heap-based buffer overflow. It is possible to launch the attack remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 6.0.8 is sufficient to resolve this issue. This patch is called 38711a3e788de0130d48cb485578c482b57d9351/4f62235b6f477b649c5cc18b0c81b4e26c949b98/4f62235b6f477b649c5cc18b0c81b4e26c949b98. You should upgrade the affected component.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Restriction of Operations within the Bounds of a Memory Buffer
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Other vulnerabilities in Kamailio
- 7.5 High severity
- 7.4 High severity
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
Recent Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerabilities
- 10.0 Critical severity
- 10.0 Critical severity
- 10.0 Critical severity
- 10.0 Critical severity
- 9.9 Critical severity
- 9.9 Critical severity
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