SAP NetWeaver Application Server (SAP Message…: Incorrect Calculation of Buffer Size
CVE-2026-120010 is a high-severity incorrect calculation of buffer size vulnerability in SAP NetWeaver Application Server (SAP Message Server) from SAP, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected SAP NetWeaver Application Server (SAP Message Server) versions: KRNL64NUC 7.22; 7.22EXT; KRNL64UC 7.22, 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 0.4% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of SAP NetWeaver Application Server (SAP Message Server) 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 |
|---|---|---|---|
| SAP | SAP NetWeaver Application Server (SAP Message Server) | KRNL64NUC 7.22; 7.22EXT; KRNL64UC 7.22; 7.53; KERNEL 7.22; 7.54; 7.77; 7.93; and 4 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
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (sap.com).
Official description
SAP NetWeaver Application Server (SAP Message Server) does not properly size memory allocations when handling certain HTTP requests. An unauthenticated attacker could send a specially crafted request to trigger a heap buffer overflow in affected functionality. Successful exploitation causes the component to abort and remain unavailable until it is restarted by the framework, resulting in a high impact on availability of the system. There is no impact on confidentiality and integrity of the application.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Calculation of Buffer Size
The product does not correctly calculate the size to be used when allocating a buffer.
How developers prevent this class of flaw
- When allocating a buffer for the purpose of transforming, converting, or encoding an input, allocate enough memory to handle the largest possible encoding. For example, in a routine that converts & characters to & for HTML entity encoding, the output buffer needs to be at least 5 times as large as the input buffer.
- Understand the programming language's underlying representation and how it interacts with numeric calculation (CWE-681). Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, not-a-number calculations, and how the language handles numbers that are too large or too small for its underlying representation. Also be careful to account for 32-bit, 64-bit, and other potential differences that may affect the numeric representation.
- Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.
More Incorrect Calculation of Buffer Size vulnerabilities (CWE-131)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
References
Other references
Recent Incorrect Calculation of Buffer Size vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.0 High severity
- 7.8 High severity
- 7.5 High severity
- 7.8 High severity
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