Description
Use After Free in the drag source path of the drag and drop protocol in kitty from 0.47.0 before 0.49.0 allows a program writing to the terminal to cause the terminal to read from and write to freed heap memory, because drag_remote_file_data() in kitty/dnd.c holds a DragRemoteItem pointer into an array it does not own, calls toplevel_data_for_drag() or subdir_data_for_drag(), and then continues to use that pointer. Those helpers, and add_payload() and populate_dir_entries() which they call, report errors through the abrt() macro, which expands to cancel_drag() followed by a plain return, and cancel_drag() calls drag_free_offer(), which frees the array the pointer refers to. The helpers return void, so the caller receives no indication that the teardown happened, and proceeds to call all_children_complete() on the freed pointer, which dereferences it, and then to write through it. That dereference is guarded by a local flag that is set when the request carries no payload and announces no further data, which is the same condition that selects the finalisation block of add_payload(), so the error paths in that block reach it: a create that fails because an entry of the same name already exists, because the client may declare two entries with one name and the create operations use O_CREAT with O_EXCL and symlinkat(), a mkdirat() failure other than EEXIST, and the directory entry allocation paths. Both branches reach it. In the top level branch the caller's pointer is never cleared, so clearing the owning structure's own pointers during teardown does not help. In the sub directory branch subdir_data_for_drag() sets the caller's pointer to NULL on entry and assigns it only after its own last error path, so its own aborts leave the caller with NULL and are stopped by a null check, but it then calls add_payload() with that pointer set, and an abort there leaves the caller holding a freed child node inside the item tree, which drag_free_offer() frees by recursion. This results in undefined behaviour in the terminal process, reachable from the byte stream of any program running in the window.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Kovid Goyal | kitty | unaffected |
|
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No data available yet.
Remediation
Vendor Solution
Upgrade to kitty 0.49.0 or later.
Tracking
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Advisories
No advisories yet.
References
History
Fri, 25 Sep 2026 16:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Use After Free in the drag source path of the drag and drop protocol in kitty from 0.47.0 before 0.49.0 allows a program writing to the terminal to cause the terminal to read from and write to freed heap memory, because drag_remote_file_data() in kitty/dnd.c holds a DragRemoteItem pointer into an array it does not own, calls toplevel_data_for_drag() or subdir_data_for_drag(), and then continues to use that pointer. Those helpers, and add_payload() and populate_dir_entries() which they call, report errors through the abrt() macro, which expands to cancel_drag() followed by a plain return, and cancel_drag() calls drag_free_offer(), which frees the array the pointer refers to. The helpers return void, so the caller receives no indication that the teardown happened, and proceeds to call all_children_complete() on the freed pointer, which dereferences it, and then to write through it. That dereference is guarded by a local flag that is set when the request carries no payload and announces no further data, which is the same condition that selects the finalisation block of add_payload(), so the error paths in that block reach it: a create that fails because an entry of the same name already exists, because the client may declare two entries with one name and the create operations use O_CREAT with O_EXCL and symlinkat(), a mkdirat() failure other than EEXIST, and the directory entry allocation paths. Both branches reach it. In the top level branch the caller's pointer is never cleared, so clearing the owning structure's own pointers during teardown does not help. In the sub directory branch subdir_data_for_drag() sets the caller's pointer to NULL on entry and assigns it only after its own last error path, so its own aborts leave the caller with NULL and are stopped by a null check, but it then calls add_payload() with that pointer set, and an abort there leaves the caller holding a freed child node inside the item tree, which drag_free_offer() frees by recursion. This results in undefined behaviour in the terminal process, reachable from the byte stream of any program running in the window. | |
| Title | Use after free in the kitty drag and drop protocol when a drag source item is aborted mid-transfer | |
| First Time appeared |
Kovidgoyal
Kovidgoyal kitty |
|
| Weaknesses | CWE-416 | |
| CPEs | cpe:2.3:a:kovidgoyal:kitty:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Kovidgoyal
Kovidgoyal kitty |
|
| References |
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| Metrics |
cvssV4_0
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MITRE
Status: PUBLISHED
Assigner: Secur0
Published:
Updated: 2026-09-25T16:59:26.692Z
Reserved: 2026-09-22T16:30:20.014Z
Link: CVE-2026-95834
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-25T17:17:20.223
Modified: 2026-09-25T17:17:20.223
Link: CVE-2026-95834
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-09-25T19:00:15Z
Weaknesses
-
CWE-416
Use After Free