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GpacApplication

CVE-2026-27821

HIGH · 7.8 CVSS v3.1 Published 2026-02-26
Fix available
A fix is available. Upgrade to after 26.02.0 or later.
See remediation →
81/100
Remediation priority · High
Public exploit No privileges Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
GPAC is an open-source multimedia framework. In versions up to and including 26.02.0, a stack buffer overflow occurs during NHML file parsing in `src/filters/dmx_nhml.c`. The value of the xmlHeaderEnd XML attribute is copied from att->value into szXmlHeaderEnd[1000] using strcpy() without any length validation. If the input exceeds 1000 bytes, it overwrites beyond the stack buffer boundary. Commit 9bd7137fded2db40de61a2cf3045812c8741ec52 patches the issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-121

Data overflows a fixed-size buffer allocated on the stack, overwriting adjacent stack memory — including saved return addresses — which is the classic route to redirecting execution into attacker-supplied code. Crafted input is all it takes. Remediation is strict length checks, safe bounded string and memory functions, and modern stack-protection mitigations.

General guidance for the stack-based buffer overflow class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
GpacApplication
Affected:<= 26.02.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 26.02.0
Vendor patch github.com →
Recommended fix Moderate confidence

Any GPAC version released after 26.02.0 that includes commit 9bd7137fded2db40de61a2cf3045812c8741ec52, or build from that specific commit

  1. 1. Verify the vulnerability exists in your current GPAC installation by checking the src/filters/dmx_nhml.c file for unchecked strcpy() usage with szXmlHeaderEnd[1000]
  2. 2. Navigate to your GPAC source directory
  3. 3. Fetch the latest source code or checkout the fixed commit: git fetch origin && git checkout 9bd7137fded2db40de61a2cf3045812c8741ec52
  4. 4. Rebuild GPAC from source: ./configure && make
  5. 5. Alternatively, check for a newer stable release of GPAC beyond version 26.02.0 that includes this security patch
  6. 6. Replace your vulnerable GPAC binary with the newly built or downloaded fixed version
  7. 7. Test that NHML file parsing functionality still works correctly with the updated version
Caveat Minimal risk - this is a security fix for a buffer overflow; no functional changes to NHML parsing behavior should occur beyond the vulnerability fix

Generated from the published advisory — verify against the referenced sources before acting.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-27821 in production — separate from our analysis above.

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What this is

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  • Version or environment caveats, and links to real fixes
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