CVE-2026-75146
HIGH 7.2 ALL-YEARSFFmpeg before commit 65b0dab contains an out-of-bounds read in the DASH demuxer (libavformat/dashdec.c). When a live DASH manifest is refreshed with a startNumber that is lower than the previous value, the current sequence number is driven negative. The fragment retrieval function checked only the upper bound before indexing the fragments array, allowing a negative index to be used and causing an out-of-bounds read. A malicious or misconfigured DASH server can trigger this by serving a live manifest with a decreasing startNumber across a manifest refresh.
Severe if exploited (CVSS 7.2), but no confirmed exploitation. Patch on a normal cadence.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 18th percentile
Impact if exploited
7.2CVSS 4.0 · HIGH · CNA
- ConfidentialityHigh
- IntegrityNone
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ⚠User interaction: Succeeds with passive user activity
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
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Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Weakness (CWE)
- CWE-125: Out-of-bounds Read
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N
References and research data (JSON)
Vendor product assessments
ffmpeg.src as a component of Red Hat Enterprise Linux AI (RHEL AI) 3 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/ffmpeg?arch=src
- workaround: No mitigation is currently available for this flaw.
- none available: Fix deferred
rhoai/odh-vllm-gaudi-rhel9 as a component of Red Hat OpenShift AI (RHOAI) · known affected
Vendor assessment for this product only.
pkg:oci/odh-vllm-gaudi-rhel9?repository_url=registry.redhat.io/rhoai/odh-vllm-gaudi-rhel9
- workaround: No mitigation is currently available for this flaw.
- none available: Fix deferred
All CVSS metrics
- HIGH 7.2 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N - HIGH 8.1 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H - HIGH 7.2 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/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 - HIGH 8.1 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
References
Patches & mitigations
- https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/65b0dab903e5975e036b30ecc58f5935d4f151e0 CVE record · VulnCheck · Updated 2026-08-19T16:28:19.356Z
NVD · CVE-2026-75146 · Updated 2026-08-31T20:37:35.877
Red Hat · CVE-2026-75146 · Updated 2026-08-28T09:21:35+00:00
Advisories
- https://www.vulncheck.com/advisories/ffmpeg-out-of-bounds-read-in-dash-demuxer-via-dashdec-c CVE record · VulnCheck · Updated 2026-08-19T16:28:19.356Z
NVD · CVE-2026-75146 · Updated 2026-08-31T20:37:35.877
Red Hat · CVE-2026-75146 · Updated 2026-08-28T09:21:35+00:00 - https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-75146.json Red Hat · CVE-2026-75146 · Updated 2026-08-28T09:21:35+00:00
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-62583 EUVD · EUVD-2026-62583
Technical & other
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24093 CVE record · VulnCheck · Updated 2026-08-19T16:28:19.356Z
NVD · CVE-2026-75146 · Updated 2026-08-31T20:37:35.877
Red Hat · CVE-2026-75146 · Updated 2026-08-28T09:21:35+00:00 - https://access.redhat.com/security/cve/CVE-2026-75146 Red Hat · CVE-2026-75146 · Updated 2026-08-28T09:21:35+00:00
- https://bugzilla.redhat.com/show_bug.cgi?id=2519764 Red Hat · CVE-2026-75146 · Updated 2026-08-28T09:21:35+00:00
- https://www.cve.org/CVERecord?id=CVE-2026-75146 Red Hat · CVE-2026-75146 · Updated 2026-08-28T09:21:35+00:00
- https://nvd.nist.gov/vuln/detail/CVE-2026-75146 Red Hat · CVE-2026-75146 · Updated 2026-08-28T09:21:35+00:00
Sources: NVD · CVE.org · All sources and attribution · EPSS