CWE-159
Improper Handling of Invalid Use of Special Elements
The product does not properly filter, remove, quote, or otherwise manage the invalid use of special elements in user-controlled input, which could cause adverse effect on its behavior and integrity.
CVE-2026-2636 (GCVE-0-2026-2636)
Vulnerability from cvelistv5 – Published: 2026-02-25 18:57 – Updated: 2026-02-26 15:56
VLAI
Title
Denial of Service in Microsoft OS
Summary
This vulnerability is caused by a CWE‑159: "Improper Handling of Invalid Use of Special Elements" weakness, which leads to an unrecoverable inconsistency in the CLFS.sys driver. This condition forces a call to the KeBugCheckEx function, allowing an unprivileged user to trigger a system crash. Microsoft silently fixed this vulnerability in the September 2025 cumulative update for Windows 11 2024 LTSC and Windows Server 2025. Windows 25H2 (released in September) was released with the patch. Windows 1123h2 and earlier versions remain vulnerable.
Severity
5.5 (Medium)
CWE
- CWE-159 - Improper Handling of Invalid Use of Special Elements
Assigner
References
1 reference
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Microsoft | Windows OS |
Affected:
0 , < 25H2
(semver)
Affected: 0 , ≤ 1123h2 (semver) |
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CVE-2026-29106 (GCVE-0-2026-29106)
Vulnerability from cvelistv5 – Published: 2026-03-19 23:02 – Updated: 2026-03-20 14:59
VLAI
Title
SuiteCRM has blind XSS in return_id parameter
Summary
SuiteCRM is an open-source, enterprise-ready Customer Relationship Management (CRM) software application. Prior to versions 7.15.1 and 8.9.3, the value of the return_id request parameter is copied into the value of an HTML tag attribute which is an event handler and is encapsulated in double quotation marks. Versions 7.15.1 and 8.9.3 patch the issue. Users should also use a Content Security Policy (CSP) header to completely mitigate XSS.
Severity
5.9 (Medium)
CWE
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/SuiteCRM/SuiteCRM/security/adv… | x_refsource_CONFIRM |
| https://docs.suitecrm.com/admin/releases/7.15.x | x_refsource_MISC |
Impacted products
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CVE-2026-35536 (GCVE-0-2026-35536)
Vulnerability from cvelistv5 – Published: 2026-04-03 02:25 – Updated: 2026-04-03 13:12
VLAI
Summary
In Tornado before 6.5.5, cookie attribute injection could occur because the domain, path, and samesite arguments to .RequestHandler.set_cookie were not checked for crafted characters.
Severity
7.2 (High)
CWE
- CWE-159 - Improper Handling of Invalid Use of Special Elements
Assigner
References
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| tornadoweb | Tornado |
Affected:
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(semver)
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Mitigation
Phases:
Description:
- Developers should anticipate that special elements will be injected/removed/manipulated in the input vectors of their software system. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.
Mitigation ID: MIT-5
Phase: Implementation
Strategy: Input Validation
Description:
- Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
- When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
- Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
Mitigation ID: MIT-28
Phase: Implementation
Strategy: Output Encoding
Description:
- While it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments. The most conservative approach is to escape or filter all characters that do not pass an extremely strict allowlist (such as everything that is not alphanumeric or white space). If some special characters are still needed, such as white space, wrap each argument in quotes after the escaping/filtering step. Be careful of argument injection (CWE-88).
Mitigation ID: MIT-20
Phase: Implementation
Strategy: Input Validation
Description:
- Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
No CAPEC attack patterns related to this CWE.