| Title | GPAC up to commit f1219cde (2026-07-25) Denial of Service |
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| Description | A vulnerability was found in GPAC up to commit f1219cde (2026-07-25) and classified as problematic. Affected is the function stbl_GetSampleInfos in the ISO media file reading logic of the component MP4Box. The manipulation via a crafted MP4 file processed with the -add argument leads to a reachable assertion failure (SampleToChunk invariant violation) that causes an immediate process abort. It is possible to launch the attack locally. User interaction is required.
Technical Details
- Affected file/function: isomedia/stbl_read.c:461 / stbl_GetSampleInfos
- Vulnerable parameter: Malformed SampleToChunk and stts box structures in the crafted MP4
- Attack vector: Local
- Privileges required: None
- Trigger condition: Processing a crafted MP4 file with "MP4Box -add" triggers assertion `stbl->SampleToChunk->firstSampleInCurrentChunk <= sampleNumber` at stbl_read.c:461. The malformed ISO file contains corrupted stts entries (133 entries with sample_delta=0) and a duplicate stts box. Requires --enable-debug build.
Impact
- Confidentiality: None
- Integrity: None
- Availability: High
CVSS v3.1
Score: 5.5 (Medium)
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Timeline
- Discovered: 2026-07-27
- Vendor notified: 2026-07-27
- Patch released: 2026-07-28
- Public disclosure: 2026-07-27
Countermeasure
Apply the upstream patch. Replace the reachable assertion with proper error handling that rejects malformed sample table structures gracefully. |
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| Source | ⚠️ https://github.com/r1ck9-2q/cve_summit/blob/main/Vuln-GPAC-MP4Box-Assertion-Failure-in-stbl-Handling.md |
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| User | r1ck9 (UID 97869) |
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| Submission | 08/02/2026 18:05 (1 month ago) |
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| Moderation | 09/12/2026 21:39 (1 month later) |
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| Status | Accepted |
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| VulDB entry | 403195 [GPAC up to f1219cde MP4Box isomedia/stbl_read.c stbl_GetSampleInfos assertion] |
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| Points | 20 |
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