NULL Pointer DereferenceWeakness · CWE-476

CVE-2026-20457

MEDIUM · 5.3 CVSS v3.1 Published 2026-07-01
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
58/100
Remediation priority · Elevated
No privileges Zero-click 7 weeks old

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
In Modem, there is a possible system crash due to improper input validation. This could lead to remote denial of service, if a UE has connected to a rogue base station controlled by the attacker, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY01826924; Issue ID: MSV-7301.

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

This is a modem vulnerability in cellular UE (User Equipment) where improper input validation allows a remote attacker controlling a rogue base station to crash the modem through malicious network signals. Since base station selection is typically automatic, any UE that connects to the attacker's network can be DoS'd without user interaction or elevated privileges.

MitigationApply the vendor-supplied firmware patch (MOLY01826924) to update the modem component. Since this is a baseband/modem issue, end users depend on device OEM/firmware updates rather than application-level mitigations.

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
Adjacent
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:A/AC:H/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 modem firmware version
    Query the modem using AT commands (e.g., AT+CGMR, ATI, or AT+CGMM) to retrieve the baseband firmware version. On Android, also check via *#*#4636#*#* or in Settings > About Phone > SIM Status. On iOS, check Settings > General > About > Modem Firmware.
    Affected if The modem firmware version is earlier than the patched version MOLY01826924, or if the version cannot be determined but the device has cellular capability.
  2. Verify cellular connectivity is enabled
    Confirm the device has an active cellular connection or SIM card present. Check network settings to confirm cellular/mobile data is turned on and the device is registered on a network.
    Affected if The device has cellular capability and connects to mobile networks, as this is the attack surface for rogue base station exploitation.
  3. Check for modem crash logs
    Review system logs for modem-related crashes or resets. On Android, use 'logcat -b radio' or check /data/log/ for modem crash dumps. On Linux-based embedded devices, check /var/log/messages or dmesg for baseband errors.
    Affected if Recent modem crashes, resets, or baseband assertion failures are present, especially after connecting to unfamiliar networks.
  4. Inspect baseband configuration
    Check modem configuration settings via AT commands (e.g., AT+CNMP for network mode, AT+COPS for operator selection). Verify if manual network selection is enabled, which could indicate exposure to rogue base stations.
    Affected if The modem is configured for automatic network selection (default behavior) and connects to any available network without operator verification.
  5. Review network connection history
    Examine the operator networks the device has connected to. Use AT+COPS=? to list available networks, or check connectivity logs for unexpected operator IDs or sudden network re-registrations.
    Affected if The device has connected to unknown or unexpected cellular networks, which could indicate interaction with a rogue base station.

A defender is affected if the device has cellular modem firmware earlier than the patched version MOLY01826924 and connects to mobile networks, as the vulnerability allows a remote attacker with a rogue base station to crash the modem without user interaction.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor-supplied firmware patch (MOLY01826924) to update the modem component. Since this is a baseband/modem issue, end users depend on device OEM/firmware updates rather than application-level mitigations.

Have this fixed Scoped from the published advisory
  • Consultation8.0 h
  • Implementation4.0 h
  • Testing16.0 h
  • Review / QA8.0 h
36.0 hours of engineering $6,160
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2026-20457 in production — separate from our analysis above.

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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
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  • Version or environment caveats, and links to real fixes
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