CVE-2026-103222
Description
A flaw was found in c-blosc2. A remote attacker could exploit this vulnerability by submitting specially crafted data to the decompression routine (blosclz_decompress). Processing this malformed input triggers an integer overflow, which can lead to memory corruption or a Denial of Service (DoS).
Statement
A flaw of moderate severity was found in the c-blosc2 compression library, in the blosclz_decompress function of blosc/blosclz.c. A remote attacker requiring no privileges or user interaction could submit specially crafted compressed data to an application or service that uses c-blosc2 for blosclz decompression; processing this malformed input triggers an integer overflow that can lead to memory corruption or a denial of service. Exploitation is considered difficult due to the high attack complexity and the specific input conditions required to trigger the overflow (Red Hat CVSS:3.1 score 5.6, Moderate, vector AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L). No Red Hat products are currently recorded as affected by this flaw: the c-blosc2 component does not match any package in Red Hat's strict package list, so no Red Hat product affects exist and no Red Hat shipping products are known to be affected at this time. The Red Hat severity rating is consistent with the upstream (CVEORG) CVSS v3 assessment of 5.6, Moderate.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. No Red Hat products are currently known to be affected. For third-party applications using an affected upstream version of c-blosc2, upgrading to upstream release 3.3.3, which contains the fix, is the available remediation.
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (Memory); DoS: Instability
This weakness can generally lead to undefined behavior and therefore crashes. When the calculated result is used for resource allocation, this weakness can cause too many (or too few) resources to be allocated, possibly enabling crashes if the product requests more resources than can be provided. If the calculated result involves time values, then the product might crash when it encounters a time that is less than the previously-calculated time.
Integrity
Technical Impact: Modify Memory
If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the overflow/wraparound results in other conditions such as buffer overflows, further memory corruption may occur.
Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism
This weakness can sometimes trigger buffer overflows, which can be used to execute arbitrary code. This is usually outside the scope of the product's implicit security policy.
Availability,Other
Technical Impact: Alter Execution Logic; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)
If the overflow/wraparound occurs in a loop index variable, this could cause the loop to terminate at the wrong time - too early, too late, or not at all (i.e., infinite loops). With too many iterations, some loops could consume too many resources such as memory, file handles, etc., possibly leading to a crash or other DoS.
Access Control
Technical Impact: Bypass Protection Mechanism
If integer values are used in security-critical decisions, such as calculating quotas or allocation limits, integer overflows can be used to cause an incorrect security decision.
Access Control
Technical Impact: Bypass Protection Mechanism; DoS: Crash, Exit, or Restart
If integer values are used in time-based, security-critical decisions, such as calculating expiration times or determining whether an event occurs within a specific time or date range, to cause an incorrect security decision. The consequences could even include "self-DoS" if the overflow produces a time value that is not accounted for in protection mechanism logic [REF-1570].
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