L-SMASH through 2.14.5 Heap Out-of-Bounds Write via hdlr and url Boxes
Summary
| CVE | CVE-2026-120456 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-11-02 15:17:29 UTC |
| Updated | 2026-11-02 18:18:52 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 6.9 MEDIUM from [email protected]
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Problem Types: CWE-787 | CWE-787 Out-of-bounds Write
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 6.9 | MEDIUM | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 6.9 | MEDIUM | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Secondary | 6.1 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H |
| 3.1 | CNA | CVSS | 6.1 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H |
CVSS v4.0 Breakdown
Attack Vector
LocalAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
PassiveConfidentiality
NoneIntegrity
LowAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
NoneIntegrity
LowAvailability
HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/l-smash/l-smash/blob/v2.14.5/core/read.c | [email protected] | github.com | |
| github.com/l-smash/l-smash/blob/v2.14.5/core/read.c | [email protected] | github.com | |
| hackmd.io/@haindpwn/lsmash-hdlr-dref-box-size-oob-write | [email protected] | hackmd.io | |
| github.com/l-smash/l-smash/commit/805ee3c9632e054198d3cb5b09c7b7aa36cdd791 | [email protected] | github.com | |
| github.com/l-smash/l-smash/issues/112 | [email protected] | github.com | |
| www.vulncheck.com/advisories/l-smash-through-2.14.5-heap-out-of-bounds-write-vi... | [email protected] | www.vulncheck.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: HaiND from the Post and Telecommunication Institute of Technology (en)
CNA: Yusuke Nakamura (en)
There are currently no legacy QID mappings associated with this CVE.