The HappySeaFox sail library, used for image loading and saving, contained an out-of-bounds write vulnerability (CWE-787) in its TGA codec's RLE decoder. Specifically, the raw-packet decoding path lacked a bounds check on the repeat count, allowing an attacker to write up to 496 bytes beyond the allocated heap buffer. This flaw was corrected in commit 45d48d1f2e8e0d73e80bc1fd5310cb57f4547302, which added the necessary bounds checking. The vulnerability has a CVSS 3.1 base score of 9.8, reflecting its critical impact on confidentiality, integrity, and availability.

Successful exploitation of this vulnerability can lead to arbitrary code execution, memory corruption, or denial of service due to heap buffer overflow. The attacker can control up to 496 bytes of data written out-of-bounds, potentially compromising the affected system or application using the vulnerable sail library version prior to the patch commit.

A fix is available in commit 45d48d1f2e8e0d73e80bc1fd5310cb57f4547302, which patches the out-of-bounds write by adding proper bounds checks in the raw-packet path of the TGA codec's RLE decoder. Users should update to this commit or a later version that includes this fix. Since this is not a cloud service, remediation requires updating the affected software. Patch status beyond the commit is not explicitly stated; verify with the vendor or project repository for official releases containing this fix.