CVE-2025-50518
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 · uneditedA use-after-free vulnerability exists in the coap_delete_pdu_lkd function within coap_pdu.c of the libcoap library. This issue occurs due to improper handling of memory after the freeing of a PDU object, leading to potential memory corruption or the possibility of executing arbitrary code. NOTE: this is disputed by the Supplier because it only occurs when an application uses libcoap incorrectly.
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 · moderate confidenceUse-after-free vulnerability in libcoap's coap_delete_pdu_lkd function in coap_pdu.c. Memory is improperly accessed after a PDU object is freed, leading to potential memory corruption and arbitrary code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify libcoap installationSearch for libcoap library files (libcoap.so, libcoap.a) or check package manager for libcoap packageAffected if libcoap is installed and being used
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Determine libcoap versionRun 'dpkg -l libcoap*' or 'rpm -qa | grep coap' or check header files for version defines (e.g., grep -r 'LIBCOAP_VERSION' /usr/include/)Affected if version cannot be determined or is prior to any available patch
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Identify applications using libcoapSearch application code for '#include <coap2/coap.h>' or '#include <coap.h>' and usage of coap_new_pdu, coap_send, coap_delete_pdu functionsAffected if application imports and uses libcoap PDU functions
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Check for PDU lifecycle management codeReview application code for patterns where coap_new_pdu is called followed by coap_delete_pdu or coap_free_pdu, and verify PDU is not accessed after deletionAffected if code contains coap_delete_pdu calls and potentially accesses PDU pointers after freeing
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Inspect for coap_delete_pdu_lkd usageSearch application and linked libraries for direct or indirect calls to coap_delete_pdu_lkd (grep -r 'coap_delete_pdu_lkd' or review disassembly of libcoap)Affected if coap_delete_pdu_lkd function is invoked in the application's runtime
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Monitor for memory corruption indicatorsRun application under memory debugging tools (ASan, Valgrind) or check dmesg for kernel memory corruption errors related to libcoap usageAffected if use-after-free or memory corruption errors are detected during runtime
The environment is affected if libcoap is present and application code handles PDU objects in a way that could trigger use-after-free in coap_delete_pdu_lkd.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataReview application code for correct usage of libcoap API to ensure PDU objects are not accessed after freeing; apply any vendor patches if available.
- Consultation4.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,656.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-50518 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-50518 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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