CWE-754
Improper Check for Unusual or Exceptional Conditions
The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.
CVE-2026-5946 (GCVE-0-2026-5946)
Vulnerability from cvelistv5 – Published: 2026-05-20 13:10 – Updated: 2026-05-20 13:40
VLAI
Title
Invalid handling of CLASS != IN
Summary
Multiple flaws have been identified in `named` related to the handling of DNS messages whose CLASS is not Internet (`IN`) — for example, `CHAOS` or `HESIOD`, or DNS messages that specify meta-classes (`ANY` or `NONE`) in the question section. Specially crafted requests reaching the affected code paths — recursion, dynamic updates (`UPDATE`), zone change notifications (`NOTIFY`), or processing of `IN`-specific record types in non-`IN` data — can cause assertion failures in `named`.
This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.
Severity
7.5 (High)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://kb.isc.org/docs/cve-2026-5946 | vendor-advisory |
| https://downloads.isc.org/isc/bind9/9.18.49 | patch |
| https://downloads.isc.org/isc/bind9/9.20.23 | patch |
| https://downloads.isc.org/isc/bind9/9.21.22 | patch |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| ISC | BIND 9 |
Affected:
9.11.0 , ≤ 9.16.50
(custom)
Affected: 9.18.0 , ≤ 9.18.48 (custom) Affected: 9.20.0 , ≤ 9.20.22 (custom) Affected: 9.21.0 , ≤ 9.21.21 (custom) Affected: 9.11.3-S1 , ≤ 9.16.50-S1 (custom) Affected: 9.18.11-S1 , ≤ 9.18.48-S1 (custom) Affected: 9.20.9-S1 , ≤ 9.20.22-S1 (custom) |
Date Public
2026-05-20 00:00
Credits
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CVE-2026-8491 (GCVE-0-2026-8491)
Vulnerability from cvelistv5 – Published: 2026-05-19 22:28 – Updated: 2026-05-20 16:36
VLAI
Title
Node View Permissions - Moderately critical - Access bypass - SA-CONTRIB-2026-034
Summary
Improper Check for Unusual or Exceptional Conditions vulnerability in Drupal Node View Permissions allows Forceful Browsing.
This issue affects Node View Permissions: from 0.0.0 before 1.7.0, from 2.0.0 before 2.0.1.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-754 - Improper Check for Unusual or Exceptional Conditions
Assigner
References
1 reference
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Drupal | Node View Permissions |
Affected:
0.0.0 , < 1.7.0
(semver)
Affected: 2.0.0 , < 2.0.1 (semver) |
Date Public
2026-05-13 17:16
Credits
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Mitigation ID: MIT-3
Phase: Requirements
Strategy: Language Selection
Description:
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- Choose languages with features such as exception handling that force the programmer to anticipate unusual conditions that may generate exceptions. Custom exceptions may need to be developed to handle unusual business-logic conditions. Be careful not to pass sensitive exceptions back to the user (CWE-209, CWE-248).
Mitigation
Phase: Implementation
Description:
- Check the results of all functions that return a value and verify that the value is expected.
Mitigation
Phase: Implementation
Description:
- If using exception handling, catch and throw specific exceptions instead of overly-general exceptions (CWE-396, CWE-397). Catch and handle exceptions as locally as possible so that exceptions do not propagate too far up the call stack (CWE-705). Avoid unchecked or uncaught exceptions where feasible (CWE-248).
Mitigation ID: MIT-39
Phase: Implementation
Description:
- Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
- If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
- Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.
- Exposing additional information to a potential attacker in the context of an exceptional condition can help the attacker determine what attack vectors are most likely to succeed beyond DoS.
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-38
Phases: Architecture and Design, Implementation
Description:
- If the program must fail, ensure that it fails gracefully (fails closed). There may be a temptation to simply let the program fail poorly in cases such as low memory conditions, but an attacker may be able to assert control before the software has fully exited. Alternately, an uncontrolled failure could cause cascading problems with other downstream components; for example, the program could send a signal to a downstream process so the process immediately knows that a problem has occurred and has a better chance of recovery.
Mitigation
Phase: Architecture and Design
Description:
- Use system limits, which should help to prevent resource exhaustion. However, the product should still handle low resource conditions since they may still occur.
No CAPEC attack patterns related to this CWE.