CyberSecBulletin
CVE-2026-58233NVD status: Awaiting Analysis

SAP Change and Transport System Attach Tool…: Deserialization of Untrusted Data

Published Updated By the CyberSecBulletin desk

CVE-2026-58233 is a high-severity deserialization of untrusted data vulnerability in SAP Change and Transport System Attach Tool (ctsattach) from SAP, with a CVSS 3.1 base score of 7.6 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. Affected SAP Change and Transport System Attach Tool (ctsattach) versions: CTS_UPLOAD_CLT 1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of SAP Change and Transport System Attach Tool (ctsattach) you run against the affected versions below, and install the vendor's latest release.
  2. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
SAPSAP Change and Transport System Attach Tool (ctsattach)CTS_UPLOAD_CLT 1Not 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
LowA basic user account is enough.
User interaction
RequiredA user must take an action such as opening a file or link.
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:L/PR:L/UI:R/S:U/C:H/I:H/A:L. Scored by CNA (sap.com).

Official description

SAP Change and Transport System Attach Tool (ctsattach) allows an authenticated attacker to supply a specially crafted archive file which, when processed by the application�s library, can trigger insecure deserialization and lead to remote code execution (RCE) on the system. Successful exploitation requires a victim to process the malicious archive, enabling the attacker to execute the RCE and extract sensitive information and gain control over the system and its processes. This vulnerability has a high impact on confidentiality and integrity of the data, with a low impact on the availability of the system.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

How developers prevent this class of flaw

  • If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
  • When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
  • Explicitly define a final object() to prevent deserialization.

More Deserialization of Untrusted Data vulnerabilities (CWE-502)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Deserialization of Untrusted Data vulnerabilities

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