CVE-2026-120456
L-SMASH through 2.14.5 Heap Out-of-Bounds Write via hdlr and url Boxes
CVSS Score
6.1
EPSS Score
0.0%
EPSS Percentile
0th
L-SMASH through 2.14.5 contains a heap out-of-bounds write vulnerability in isom_read_hdlr() and isom_read_dref_entry() in core/read.c triggered by oversized box sizes. Attackers can supply crafted MP4 or MOV files declaring hdlr or url box sizes larger than remaining data, stalling the stream position and corrupting heap memory to crash applications.
| CWE | CWE-787 |
| Vendor | l-smash |
| Product | l-smash |
| Published | Nov 2, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
High
Affected Versions
L-SMASH / L-SMASH
0 ≤ 2.14.5
References
github.com: https://github.com/l-smash/l-smash/issues/112 github.com: https://github.com/l-smash/l-smash/commit/805ee3c9632e054198d3cb5b09c7b7aa36cdd791 github.com: https://github.com/l-smash/l-smash/blob/v2.14.5/core/read.c#L688-L717 github.com: https://github.com/l-smash/l-smash/blob/v2.14.5/core/read.c#L853-L876 hackmd.io: https://hackmd.io/@haindpwn/lsmash-hdlr-dref-box-size-oob-write vulncheck.com: https://www.vulncheck.com/advisories/l-smash-through-2.14.5-heap-out-of-bounds-write-via-hdlr-and-url-boxes
Credits
HaiND from the Post and Telecommunication Institute of Technology Yusuke Nakamura