SAP NetWeaver Application Server for ABAP and…: Integer Underflow (Wrap or Wraparound)
CVE-2026-66767 is a high-severity integer underflow (wrap or wraparound) vulnerability in SAP NetWeaver Application Server for ABAP and ABAP Platform from SAP, with a CVSS 3.1 base score of 7.7 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 for ABAP and ABAP Platform 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 0.43% 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 for ABAP and ABAP Platform 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 for ABAP and ABAP Platform | KRNL64NUC 7.22; 7.22EXT; KRNL64UC 7.22; 7.53; 8.04; KERNEL 7.22; 7.54; 7.77; and 5 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
- HighSuccess depends on conditions outside the attacker's control.
- 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
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L. Scored by CNA (sap.com).
Official description
SAP NetWeaver Application Server for ABAP and ABAP Platform allows an unauthenticated user to send a specially crafted packet that triggers reprocessing of a previously buffered user request, potentially hijacking another user's session under narrow timing conditions. Successful exploitation could result in high impact on confidentiality and integrity, with low impact on availability of the application.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Integer Underflow (Wrap or Wraparound)
The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.
More Integer Underflow (Wrap or Wraparound) vulnerabilities (CWE-191)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in SAP NetWeaver Application Server for ABAP and ABAP Platform
- 9.9 Critical severity
- 9.0 Critical severity
- 8.8 High severity
Recent Integer Underflow (Wrap or Wraparound) vulnerabilities
- 7.0 High severity
- 7.5 High severity
- 7.5 High severity
- 8.7 High severity
- 8.7 High severity
- 9.6 Critical severity
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