CVE-2026-20459
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 · uneditedIn 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: MOLY01816800; Issue ID: MSV-6842.
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 · high confidenceIn the Modem component, improper input validation allows a remote attacker controlling a rogue base station to cause a system crash on connected User Equipment (UE), resulting in denial of service. No user interaction is required, and exploitation does not need additional execution privileges beyond the UE connecting to the malicious base station.
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 checksWork through these to decide whether this CVE applies to you.
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Identify modem-equipped deviceDetermine if the system contains a cellular modem component (UE - User Equipment such as phones, tablets, IoT devices, M2M modules)Affected if Device has an integrated cellular modem for connectivity
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Check modem firmware versionAccess modem firmware information through AT commands (e.g., AT+CGMR), modem diagnostics interface, or vendor management consoleAffected if Firmware version cannot be verified or is earlier than vendor patch MOLY01816800
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Verify cellular network connection capabilityConfirm the device is configured to connect to cellular networks (3G/4G/5G)Affected if Device automatically connects to untrusted or unauthenticated cellular networks
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Review base station connection settingsCheck if modem is set to connect to any available network or if there are restrictions on trusted/authorized networksAffected if Modem accepts connections from any base station without network authentication verification
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Inspect mobile network operator configurationLook for SIM/USIM configuration and whether the device verifies network operator credentials before attachingAffected if Device lacks network authentication verification and connects to rogue base stations
User is affected if their device has a cellular modem component and connects to cellular networks, unless the modem firmware has been patched to MOLY01816800 or later with network authentication controls enabled.
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 dataApply vendor patch MOLY01816800 to the modem firmware. Additionally, ensure UE devices are configured to only connect to trusted/authorized cellular networks and implement network authentication verification where possible.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,096.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20459 — 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-2026-20459 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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- 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