libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call depth tracking for various calls from within handlers in cases of a policy violation. Thus, a use-after-free can occur. NOTE: this issue exists because of an incomplete fix for CVE-2026-50219.
Weakness
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Matanza | Ubuntu | devel | * |
| Matanza | Ubuntu | esm-apps/focal | * |
| Matanza | Ubuntu | esm-apps/jammy | * |
| Matanza | Ubuntu | esm-apps/noble | * |
| Matanza | Ubuntu | esm-apps/resolute | * |
| Matanza | Ubuntu | jammy | * |
| Matanza | Ubuntu | noble | * |
| Matanza | Ubuntu | questing | * |
| Matanza | Ubuntu | resolute | * |