In Libav 12.3, there is a heap-based buffer over-read in vc1_decode_b_mb_intfi in vc1_block.c that allows an attacker to cause denial-of-service via a crafted file.
CVSS v4.0 Metrics
Exploitability
Attack VectorNetwork
ComplexityLow
RequirementsPresent
PrivilegesNone
User InteractionActive
Threat
Exploit MaturityPoC
Vulnerable System
ConfidentialityNone
IntegrityNone
AvailabilityHigh
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | PoC | E: U→P | 2.1 → 5.0 |
| 2026-07-21 | nvd | AV: P→N, AC: H→L, PR: H→N, VA: N→H | 0.0 → 2.1 |
| 2026-07-21 | cve.org | initial, patch: Unavailable | 0.0 |
Affected Software
| Vendor | Product | Version |
|---|
| libav | libav | 12.3 |
Published: 2021-08-23
