Cybersecurity professionals consider CVE-2026-56711 an immediate threat requiring urgent mitigation.
Status: Deferred
Published on: 09 Sep 2026, 14:17 UTC
CVSS Release: version 3
disclosure@vulncheck.com
Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVE-2026-56711: VLC media player computes the size of a picture buffer with 32-bit arithmetic and allocates from the wrapped result. In AllocatePicture in src/misc/picture.c the running total is accumulated as i_bytes += p->i_pitch * p->i_lines, and both plane_t fields are declared int in include/vlc_picture.h, so the multiplication is evaluated at 32 bits and wraps before it is widened to the size_t accumulator. The overflow check that precedes it divides in 64-bit arithmetic and therefore does not constrain the product, and the subsequent comparison against PICTURE_SW_SIZE_MAX examines the already wrapped value, so both guards pass. aligned_alloc then reserves the small wrapped size while the decoder writes scanlines sized from the original dimensions. A crafted PNG whose IHDR declares large width and height reaches this path through the image demuxer, whose only size guard is on the input file's byte count rather than the declared dimensions, and the decoder in modules/codec/png.c writes past the end of the allocation with attacker-influenced length and content. Opening the file directly or through a playlist entry is sufficient, with no non-default settings.
The exploitability of CVE-2026-56711 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
With low attack complexity and no required privileges, CVE-2026-56711 is an easy target for cybercriminals. Organizations should prioritize immediate mitigation measures to prevent unauthorized access and data breaches.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2026-56711, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2026-56711, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
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