dbcve.org
Mbed TlsApplication · Arm

CVE-2025-48965

HIGH · 7.5 CVSS v3.1 Published 2025-07-20
Fix available
A fix is available. Upgrade to 3.6.4 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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
Mbed TLS before 3.6.4 has a NULL pointer dereference because mbedtls_asn1_store_named_data can trigger conflicting data with val.p of NULL but val.len greater than zero.

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 confidence

Mbed TLS before version 3.6.4 contains a NULL pointer dereference vulnerability in the ASN.1 parsing code. The function mbedtls_asn1_store_named_data can encounter conflicting data where the pointer (val.p) is NULL but the length (val.len) is greater than zero, triggering the NULL pointer dereference. This affects applications using Mbed TLS for ASN.1 certificate or key parsing.

MitigationUpgrade Mbed TLS to version 3.6.4 or later to patch the NULL pointer dereference in the ASN.1 parsing code.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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
Mbed TlsApplication
Affected:< 3.6.4

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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify Mbed TLS installation
    Locate the mbedtls library files (libmbedtls.so, mbedtls.dll, or mbedtls.lib) or header files in your environment. Check common library directories or search for 'mbedtls' in installed packages using your system's package manager.
    Affected if Mbed TLS library is present in the system
  2. Determine installed Mbed TLS version
    Run 'mbedtls --version' if the command-line tool is installed, or inspect the library binary's metadata/version info. Alternatively, check the mbedtls/version.h header file if source code is available, looking for MBEDTLS_VERSION_NUMBER or MBEDTLS_VERSION_MAJOR/MINOR/PATCH macros.
    Affected if The version number is less than 3.6.4 (for example, 3.6.0, 3.5.x, or earlier)
  3. Verify ASN.1 parsing is in use
    Review application code or configuration to confirm it uses Mbed TLS functions for ASN.1 certificate parsing (such as mbedtls_x509_crt_parse, mbedtls_pk_parse_key) or CRL/CSR parsing functions.
    Affected if The application parses X.509 certificates, keys, or other ASN.1 structures using Mbed TLS
  4. Check for vulnerable code path
    Inspect the mbedtls_asn1_store_named_data function in your Mbed TLS library binary or source code. The vulnerability triggers when storing named data elements where the value pointer is NULL but the length is non-zero during ASN.1 DER parsing.
    Affected if The library contains the vulnerable ASN.1 parsing code and processes potentially malformed ASN.1 input

You are affected if Mbed TLS version is below 3.6.4 AND your application uses Mbed TLS to parse ASN.1-encoded certificates or keys from untrusted sources.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 3.6.4 or later
Fixed in 3.6.4
Interim mitigation

Upgrade Mbed TLS to version 3.6.4 or later to patch the NULL pointer dereference in the ASN.1 parsing code.

Recommended fix High confidence

Mbed TLS 3.6.4

  1. 1. Identify the current Mbed TLS version in your deployment by checking your dependency manifest or running `git log` or package manager query
  2. 2. Obtain Mbed TLS version 3.6.4 or later from the official repository at github.com/Mbed-TLS/mbedtls or your distribution's package repository
  3. 3. Replace or update the existing Mbed TLS installation with version 3.6.4, following your project's standard library update procedure (e.g., updating submodule, rebuilding, or reinstalling packages)
  4. 4. Rebuild and test your application to verify the update was successful and no regressions were introduced
  5. 5. Confirm the vulnerable function mbedtls_asn1_store_named_data no longer exhibits the NULL pointer dereference behavior described in the CVE
Caveat Minor release; likely minimal breaking changes as this addresses a bug fix, but review the release notes for any deprecation notices

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

Fix this in Mbed Tls Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,570
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,512.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-48965 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2025-48965 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data