What is CVE-2026-56711?

CVE-2026-56711 is VLC media player 3.0.0 through 3.0.23 Heap Out-of-Bounds Write via Integer Overflow in Picture Allocation. The supplied enrichment data classifies it as Memory Corruption mapped to CWE-190 Integer Overflow or Wraparound; CWE-787 Out-of-bounds Write.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-56711. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-56711 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

A public PoC is not confirmed from current sources for CVE-2026-56711. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-56711 using CVSS 8.8, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

highMemory Corruption

CVE-2026-56711

CVE-2026-56711 — VLC media player 3.0.0 through 3.0.23 Heap Out-of-Bounds Write via Integer Overflow in Picture Allocation

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.

Published Sep 9, 2026Updated Sep 9, 2026Sources: NVD, VideoLAN (CNA), GitHub, Red Hat (VEX), SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

ahead of 0% of scored CVEs

Affects

VideoLAN

VLC media player

CVSS base

8.8

high · 2 sources

Remediation

The vendor's own words where we have them.

Upgrade VLC media player to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

Red Hat VEX · CVE-2026-56711

fixed0affected0not affected1

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
VideoLAN	VLC media player	3.0.0 to <= 3.0.23	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

High

Confidentiality

High

Integrity

High

Scope

Unchanged

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

Required

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
8.8	CVSS 3.1	high	2.8	5.9	NVD, VideoLAN (CNA), Red Hat (VEX)
8.6	CVSS 4.0	high	—	—	VideoLAN (CNA)

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-190 · Integer Overflow or Wraparound

DoS: Crash, Exit, or Restart
DoS: Resource Consumption (CPU)
DoS: Resource Consumption (Memory)
DoS: Instability

Mitigation: Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.

CWE-787 · Out-of-bounds Write

Modify Memory
DoS: Crash, Exit, or Restart
Execute Unauthorized Code or Commands::

Mitigation: Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.

Weakness & attack patterns

CWE-190Integer Overflow or Wraparound
CWE-787Out-of-bounds Write

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-92 · Forced Integer Overflow

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Search application, proxy, and WAF logs for requests touching /misc/picture.c, /vlc_picture.h, /codec/png.c.
Prioritize edge telemetry for network-reachable VLC media player.

web/proxy/WAF logsapplication logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 8.8 (AV:N)
Sep 9, 2026 · NVD
Initial · CVE published
Sep 9, 2026 · NVD
CVE published by MITRE.
Sep 9, 2026 · SOCRadar CTI

References

9 on the record

github.com/videolan/vlc
Exploit, Third Party Advisory
github.com/videolan/vlc/blob/3.0.23/include/vlc_picture.h
Exploit, Third Party Advisory
github.com/videolan/vlc/blob/3.0.23/modules/codec/png.c
Exploit, Third Party Advisory
github.com/videolan/vlc/blob/3.0.23/modules/demux/image.c
Exploit, Third Party Advisory
github.com/videolan/vlc/blob/3.0.23/src/misc/picture.c
Exploit, Third Party Advisory
www.vulncheck.com/advisories/vlc-media-player-3.0.0-through-3.0.23-heap-out-of-bounds-write-via-integer-overflow-in-picture-allocation
Vendor Advisory, Mitre
access.redhat.com/security/cve/CVE-2026-56711
Vendor Advisory
www.cve.org/CVERecord?id=CVE-2026-56711
Vendor Advisory

Elsewhere on this site

VideoLANevery CVE for this vendor
Memory Corruptionsame class
CWE-190other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-56711 is VLC media player 3.0.0 through 3.0.23 Heap Out-of-Bounds Write via Integer Overflow in Picture Allocation, a high vulnerability affecting VLC media player from VideoLAN. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-56711. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2026-56711. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 8.8 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.