CVE-2026-20884
Description
A flaw was found in LibRaw. An integer overflow vulnerability in the deflate_dng_load_raw functionality allows a remote attacker to provide a specially crafted malicious file. This can lead to a heap buffer overflow, potentially resulting in arbitrary code execution.
Statement
This flaw in the LibRaw library consists in an integer overflow in the deflate_dng_load_raw() function, a successfully performed attack may lead to a heap buffer overflow and potentially arbitrary code execution or denial of service. The vulnerability stems from the usage of a 32-bit arithmetic to calculate the memory limits and the buffer allocation size for the image's tile dimension values, which may end up overflowing when processing user controlled images as input. The calculation result is further used within 64-bit boundary checking however the proper cast is missing and the result value is used to allocate the buffer from memory, when the overflow happens the function may start writing outside of the expected memory boundary leading to data corruption.
This vulnerability is not exploitable when the application consuming LibRaw is using the default memory limit (max_raw_memory_mb parameter) to unpack the RAW image. To be considered vulnerable the application should be setting the limit to around or greater then 11GB.
Red Hat Product Security has rated this vulnerability as having a Moderate impact, despite the possibility of arbitrary code execution due to the heap-based buffer overflow, as the user needs to be tricked to process a maliciously crafted image or LibRaw needs to be exposed to the network and accepting untrusted data as input. Additionally the default max_raw_memory_mb value set with LibRaw is not enough to trigger the vulnerability.
Mitigation
This vulnerability can be mitigated by limiting the amount of memory used to unpack untrusted RAW images. This needs to be set in the application using the LibRaw and can be achieved by setting the `max_raw_memory_mb` to a value smaller than 16GB.
This parameter can't be changed in runtime in the library, so developers needs to patch and rebuild their application to impose the new limit. It's important to notice the fact when reducing the memory limit for the decoding process may render the library unable to handle big images.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | 9.8 | 8.1 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | High | Low | High |
| Privileges Required | None | None | None |
| User Interaction | Required | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
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.
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