A heap-based buffer over-read vulnerability was found in the X.org server's ProcXIGetSelectedEvents function. This issue occurs when byte-swapped length values are used in replies, potentially leading to memory leakage and segmentation faults, particularly when triggered by a client with a different endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory values and then transmit them back to the client until encountering an unmapped page, resulting in a crash. Despite the attacker's inability to control the specific memory copied into the replies, the small length values typically stored in a 32-bit integer can result in significant attempted out-of-bounds reads. A heap-based buffer over-read vulnerability was found in the X.org server's ProcXIPassiveGrabDevice function. This issue occurs when byte-swapped length values are used in replies, potentially leading to memory leakage and segmentation faults, particularly when triggered by a client with a different endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory values and then transmit them back to the client until encountering an unmapped page, resulting in a crash. Despite the attacker's inability to control the specific memory copied into the replies, the small length values typically stored in a 32-bit integer can result in significant attempted out-of-bounds reads. The ProcRenderAddGlyphs function calls the AllocateGlyph function to store new glyphs sent by the client to the X server. AllocateGlyph would return a new glyph with refcount=0 and a re-used glyph would end up not changing the refcount at all. The resulting glyph_new array would thus have multiple entries pointing to the same non-refcounted glyphs.ProcRenderAddGlyphs may free a glyph, resulting in a use-after-free when the same glyph pointer is then later used