LiveActive security incident?Get immediate response
CVE Record

CVE-2026-32836: mackron / dr_libs dr_flac.h Excessive Memory Allocation in PICTURE Metadata Parsing

dr_libs dr_flac.h version 0.13.3 and earlier (fixed in commits fefced4, 4f5a4cd, and 663239a) contain an uncontrolled memory allocation vulnerability in drflac__read_and_decode_metadata() that allows attackers to trigger excessive memory allocation by supplying crafted PICTURE metadata blocks. Attackers can exploit attacker-controlled mimeLength and descriptionLength fields to cause denial of service through memory exhaustion when processing FLAC streams with metadata callbacks.

MediumCVSS 6.9Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

A crafted FLAC file can make affected software allocate excessive memory while reading embedded picture information. This can exhaust memory and stop the application or service. The evidence supports denial of service, not data theft or code execution.

Executive priority

Prioritize internet-facing or automated media-processing systems because memory exhaustion could disrupt service availability. Address exposed workloads promptly through dependency remediation and resource controls. Lower the priority for systems that do not process untrusted FLAC input or do not enable the relevant metadata callback path, after validating those assumptions.

Technical view

dr_flac.h 0.13.3 and earlier insufficiently constrain attacker-controlled mimeLength and descriptionLength values in PICTURE metadata processing within drflac__read_and_decode_metadata(). When metadata callbacks are enabled, malicious values can drive uncontrolled allocation and cause availability loss through memory exhaustion. The issue is classified as CWE-789 with CVSS 4.0 score 6.9.

Likely exposure

Exposure requires an affected dr_flac.h copy, FLAC processing with metadata callbacks, and attacker-influenced FLAC input. Media services, upload processors, and applications opening untrusted FLAC files warrant review. Products embedding the header may not expose their dependency version clearly, so source or binary inventory may be necessary.

Exploitation context

The supplied record lists CVSS attack vector Local, no privileges, no user interaction, and high availability impact. It is not listed in KEV, and the supplied sources do not establish active exploitation. Network-facing applications could still expose the vulnerable parsing path if they automatically process uploaded or otherwise untrusted FLAC streams.

Researcher notes

The vulnerable behavior is tied to PICTURE metadata allocation using attacker-controlled MIME and description lengths. The source bundle identifies three fixing commits, suggesting remediation may span related allocation paths; verify all applicable changes rather than assuming one commit is sufficient. No confidentiality or integrity impact, exploit-in-the-wild evidence, or affected downstream product list is established here.

Mitigation direction

  • Update dr_flac.h to vendor-fixed code containing the referenced commits.
  • Backport all applicable vendor changes if immediate dependency replacement is impractical.
  • Restrict or suspend automatic processing of untrusted FLAC metadata until remediated.
  • Apply memory and process limits to reduce denial-of-service impact.

Validation and detection

  • Inventory applications and vendored source trees for dr_flac.h 0.13.3 or earlier.
  • Confirm whether FLAC metadata callbacks process PICTURE blocks from untrusted inputs.
  • Verify the deployed source contains the referenced corrective commits or their released equivalent.
  • Test malformed metadata handling under controlled memory monitoring without using production systems.
  • Confirm affected services recover safely when media parsing exceeds resource limits.
Prepared
Confidence
high
Sources
7

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-789: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-32836 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.9 (4.0)
Known Exploited
No
Published

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
3Timeline events
1ADP providers
6Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.9CVSS 4.0MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——VulnCheck
6.2CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H2.53.6VulnCheck

Vulnerability scoring details

Base CVSS 4.0 score

6.9Medium
CVSS 4.0 vector shape for CVE-2026-32836Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
mackrondr_libs dr_flac.h0, fefced4a64adfb1a68a2d31d882366e56096dee8, 4f5a4cd3b57564d969443c580c75857e039f100a, 663239a3d0460c33bd5b6e5166edcb404e3df676unknown
Weakness

CWE details

CWE-789

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-789 · source CWE mapping

Memory Allocation with Excessive Size Value

Memory Allocation with Excessive Size Value represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs