CVE-2026-12912
Description
A flaw was found in libtiff. A remote attacker could exploit this vulnerability by providing a specially crafted PixarLog-compressed TIFF image. This issue occurs when decoding Pixarlog codec images with the PIXARLOGDATAFMT_8BITABGR output format and a specific stride value, leading to a heap-based buffer overflow. This could potentially result in arbitrary code execution or a denial of service (DoS).
Statement
This is an Important heap-based buffer overflow in libtiff affecting applications that explicitly configure the library to decode Pixarlog-compressed TIFF images using the PIXARLOGDATAFMT_8BITABGR output format with SamplesPerPixel == 3. Standard image reading functions, such as TIFFReadRGBAImage, are not directly impacted as they do not typically select this specific format. Exploitation requires processing a specially crafted TIFF image under these specific conditions.
Mitigation
To mitigate this issue, applications processing untrusted TIFF images should avoid explicitly configuring `PIXARLOGDATAFMT_8BITABGR` when decoding PixarLog-compressed TIFF images with three samples per pixel. This specific combination of output format and samples per pixel is required to trigger the heap-based buffer overflow.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.3 | N/A | 7.3 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
Integrity,Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Modify Memory
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy. Besides important user data, heap-based overflows can be used to overwrite function pointers that may be living in memory, pointing it to the attacker's code. Even in applications that do not explicitly use function pointers, the run-time will usually leave many in memory. For example, object methods in C++ are generally implemented using function pointers. Even in C programs, there is often a global offset table used by the underlying runtime.
Integrity,Confidentiality,Availability,Access Control,Other
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Other
When the consequence is arbitrary code execution, this can often be used to subvert any other security service.
Acknowledgements
Red Hat would like to thank Ariel Schön for reporting this issue.
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