Cisco Field Notices

Field Notices are notifications that are published for significant issues, other than security vulnerability-related issues, that directly involve Cisco products and typically require an upgrade, workaround, or other customer action. 

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Locate Field Notices most relevant to you. A Field Notice may be labeled as "Expired" on Cisco.com once the product issue becomes obsolete or all affected products reach their end of support date. Cisco provides the information contained on this page and all Field Notices officially in English only.


 

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918 Results
Field Notice #
Description
Recommended action
Impact rating

Cisco publishes Field Notices to notify customers and partners about significant issues in Cisco products that typically require an upgrade, workaround, or other user action.

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Last updated
FN74438
Upgrade from Cisco BroadWorks Media Server Release 2025.06_1.254 May Fail Due to Missing Configuration Elements
Workaround Provided
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Unified Communications
Sep 4, 2026
FN74414
A Firmware Issue in Some Cisco NCS 5500 Series Routers May Cause Filesystem to Be Remounted to Read-Only Mode, Resulting in Kernel Panic
Software Upgrade Recommended
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Routers
Sep 4, 2026
FN74415
Firmware Issue in Cisco ASR9000 Series Routers May Cause Filesystem to Be Remounted to Read-Only Mode, Resulting in Kernel Panic
Software Upgrade Recommended
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Routers Switches
Sep 1, 2026
FN74418
Cisco Remote PHY Device Software Upgrade to Release 10.9.1 Required Due to Cable Labs Certificate
Workaround Provided
Low Unlikely to expect disrupted functionality
Video
Aug 27, 2026
FN74419
Some Cisco Network Convergence System 540 Series Routers Fail to Boot After SSD Firmware Backported from Firmware 1616 to 1402 on Software Releases Earlier than 26.2.x
Software Upgrade Recommended
High May degrade or might have a potential degradation
Routers
Aug 20, 2026
FN74344
Cisco Catalyst IE-3100-18T2C-E and IE-3100-18T2C-CC-E Switches Hardware Update Requires Minimum Software Release
Software Upgrade Recommended
High May degrade or might have a potential degradation
Switches
Aug 20, 2026
FN74423
Enhancing SyncE/PTP Clock Recovery Reliability for Cisco 8712-MOD-M Units
Software Upgrade Recommended
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Routers
Jul 30, 2026
FN74186
Certain Operations on Nexus Dashboard Insights May Cause an ACI Switch Reload
Software Upgrade Recommended
High May degrade or might have a potential degradation
Switches
Jul 28, 2026
FN74352
Cisco 8711-32FH-M Routers Running a Cisco IOS XR Release Earlier than Release 25.4.2 May Encounter Interface Failure Resulting in No Traffic Flow
Software Upgrade Recommended
High May degrade or might have a potential degradation
Routers
Jul 22, 2026
FN74417
Cisco UCS 6454 Fabric Interconnects May Enter Reboot Loop During Firmware Upgrade to Release 4.3(6.250094) or Later
Configuration Change Recommended
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Servers - Unified Computing
Jul 20, 2026
FN63944
ASR 920 1G Ports Do Not Come Up on Cisco IOS Software Release 15.5(1)S (3.14.0)
Software Upgrade Recommended
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Routers
Jul 16, 2026
FN72292
Cisco Nexus 92348GC-X Switch Bootflash Size Is Less Than Expected
Workaround Provided
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Switches
Jul 9, 2026
FN74402
Automatic Upgrade of FPDs May Not Complete During Cisco IOS XR Software Update on Enhanced XR Platforms
Workaround Provided
High May degrade or might have a potential degradation
IOS and NX-OS Software Optical Networking Routers
Jun 26, 2026
FN74351
Cisco Secure Web Appliance: Legacy Protocol for AMP File Reputation Going End of Life
Software Upgrade Recommended
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Security
Jun 26, 2026
FN74156
DP04SFP8-E20 Might Experience Performance Degradation
Replace on Failure
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Cisco Interfaces and Modules
Jun 24, 2026
FN74350
Cisco Unified Border Element: Impact on Secure Communication Due to Upcoming Changes to TLS Certificates Issued by Public Certificate Authorities with Client Authentication EKU, Starting May 2026
Workaround Provided
Critical May experience downtime or might be at risk of affecting services
Cisco Interfaces and Modules Routers
Jun 23, 2026
FN74409
A Small Number of Cisco Nexus Dashboard ND-NODE-G5S Nodes Are Running an Incorrect Software Release
Software Upgrade Recommended
High May degrade or might have a potential degradation
Data Center Networking
Jun 17, 2026
FN72464
Cisco Nexus 9300 Switches and APIC Servers Can Experience Memory Failures
Hardware Upgrade Available
Low Unlikely to expect disrupted functionality
Cloud and Systems Management Switches
Jun 17, 2026
FN74305
Cisco Network Convergence Systems 2000 Series Multirate Muxponder Line Cards May Report Non-Impacting EQPT-DEGRADE Alarm
Software Upgrade Recommended
Low Unlikely to expect disrupted functionality
Cisco Interfaces and Modules Optical Networking
Jun 10, 2026
FN74408
Cisco BroadWorks Application Server 2026.04_1.232 May Experience OCI XML Parsing Failure When Single-Quoted Attribute Values Are Used
Software Upgrade Recommended
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Unified Communications
Jun 2, 2026
FN74362
Cisco Expressway: Impact on Secure Communication due to Upcoming Changes to TLS Certificates Issued by Public Certificate Authorities with Client Authentication EKU, Starting May 2026
Workaround Provided
Critical May experience downtime or might be at risk of affecting services
Unified Communications
Jun 1, 2026
FN74254
Limited Number of Cisco Network Convergence System 540 and 560 Series Routers May Experience Memory Failure
Hardware Upgrade Available
Critical May experience downtime or might be at risk of affecting services
Cisco Interfaces and Modules Routers
May 29, 2026
FN74403
Cisco Identity Services Engine Shared Memory Allocation Errors Causing Replication Failures, GUI Access Issues, and Authentication Disruptions
Software Upgrade Recommended
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Security
May 27, 2026
FN74400
Some Cisco Network Convergence System 540 Series Routers Will Exhibit Continuous Boot Loop During Upgrade to Cisco IOS XR Software Release 26.1.1 or Later
Software Upgrade Recommended
Critical May experience downtime or might be at risk of affecting services
Routers
May 26, 2026
FN74383
Cisco Access Points That Are Running, Or Have Run, Releases 17.12.4, 17.12.5, 17.12.6, or 17.12.6a May Exhaust Flash Space, Preventing Upgrades
Software Upgrade Recommended
Critical May experience downtime or might be at risk of affecting services
Switches Wireless
May 19, 2026
FN74382
Cisco Unified Contact Center Products: Impact on Secure Communication Due to Upcoming Changes to TLS certificates Issued by Public Certificate Authorities with Client Authentication EKU, Starting March 2027
Workaround Provided
Critical May experience downtime or might be at risk of affecting services
Contact Center
May 13, 2026
FN74397
Cisco Catalyst Center Server Certificate Client EKU Is Not Supported by Public Certficate Authorities after May 15, 2026
Software Upgrade Recommended
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Cloud and Systems Management
May 13, 2026
FN74391
When Adding Large Numbers of VLANs to a vNIC, Redundant Fabric Interconnects May Both Restart
Software Upgrade Recommended
High May degrade or might have a potential degradation
Servers - Unified Computing
May 8, 2026
FN74269
Cisco NCS 5500 Modular Systems May Not Work Properly During Replacement or Reimage for Systems Containing Third-Party SMUs
Software Upgrade Recommended
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Routers
May 4, 2026
FN74264
Cisco ASR 9000 Series Modular Systems May Not Work Properly During Replacement or Reimage for Systems Containing Third-Party SMUs
Software Upgrade Recommended
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
IOS and NX-OS Software Routers
May 4, 2026
FN74395
Cisco Secure Firewall Threat Defense Software: VaultApp Process Might Cause Instability for Cisco Secure Firewall Devices
Software Upgrade Recommended
Critical May experience downtime or might be at risk of affecting services
Security
May 1, 2026
FN74148
PAK and RTU Licenses Cannot Be Converted to Smart Licenses When Doing Direct (Long-Jump) Upgrades from Cisco IOS XE Software Release 17.3 or Earlier to Release 17.11 or Later
Workaround Provided
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Cisco Interfaces and Modules Routers Wireless
Apr 20, 2026
FN74404
Cisco Secure Network Analytics: Impact on Secure Communications from Public CA Client Authentication EKU Changes Starting May 2026
Workaround Provided
Critical May experience downtime or might be at risk of affecting services
Security
Apr 17, 2026
FN74365
Cisco Unity Connection Unified Messaging with Microsoft 365 - Voicemail Stored in Cisco Unity Connection Will Not Sync with Exchange Online (Outlook) Due to EWS Deprecation
Software Upgrade Recommended
High May degrade or might have a potential degradation
Unified Communications
Apr 15, 2026
FN74297
Some Cisco Network Convergence System 540 Series Routers — N540X-6Z18G-SYS-D and N540X-4Z14G2Q-D — May Fail When Subjected to 4kV Common Mode Surge Voltage
Replace on Failure
High May degrade or might have a potential degradation
Routers
Apr 2, 2026
FN74386
Cisco IOS XR Software May Display False Fan Alarms and/or Outputs for PSU2KW Power Supplies
Software Upgrade Recommended
Low Unlikely to expect disrupted functionality
Routers
Apr 1, 2026
FN74345
Cisco On-Premises Calling Products: Impact on Secure Communication Due to Upcoming Changes to TLS certificates Issued by Public Certificate Authorities with Client Authentication EKU, Starting May 2026
Workaround Provided
Critical May experience downtime or might be at risk of affecting services
Unified Communications
Mar 31, 2026
FN74337
Cisco 8202-32FH-M SUDI Authentication Failed/Serial Number Mismatch
Software Upgrade Recommended
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Routers
Mar 27, 2026
FN74375
Cisco Jabber Clients (Windows and Mac) End Users Cannot Join Cisco Webex Meetings after July 31, 2026
Software Upgrade Recommended
Critical May experience downtime or might be at risk of affecting services
Unified Communications
Mar 18, 2026
FN74348
Cisco Unified Contact Center Enterprise and Cisco Cloud Connect Orchestration Feature May Fail to Connect after May 4, 2026
Software Upgrade Recommended
Critical May experience downtime or might be at risk of affecting services
Contact Center
Mar 18, 2026
FN74306
Cisco ASR 9K Routers Software Upgrade Issue: Sunstreaker/Sigma/LongShot and TAMFW FPD Upgrade Timeout or FPGA Corruption
Workaround Provided
High May degrade or might have a potential degradation
Routers
Mar 16, 2026
FN74335
Cisco ASR 9000 Series 5th Generation 400 Gigabit Ethernet Enhanced Multi-Rate Line Cards with device_revision 2 Requires Cisco IOS XR Software Release 25.2.2 and Later to Function Properly
Software Upgrade Recommended
High May degrade or might have a potential degradation
IOS and NX-OS Software Routers
Mar 4, 2026
FN74290
A Few Cisco Network Convergence System 2000 Series Shelf Virtualization Orchestrator Line Cards Might Experience Unpredictable Results, Become Unreachable, or Both When Upgraded to Software Release 25.1.1
Hardware Upgrade Available
Medium May affect system performance or functionality but are less likely to pose an immediate risk to the network
Optical Networking
Mar 4, 2026
FN74353
Cisco Network Convergence Systems 560 Series Routers May Not Display Accurate Fan Speed Readings upon Occurrence of Fault in the Fans Impacting Router Operation
Software Upgrade Recommended
High May degrade or might have a potential degradation
Routers
Feb 20, 2026
FN70601
Some Cisco vEdge 100M Routers Might Fail to Detect the SIM Card
Replace on Failure
Low Unlikely to expect disrupted functionality
Routers
Feb 20, 2026
FN74342
Cisco Unified Communications Manager: SMTP May Fail to Connect After March 1, 2026
Workaround Provided
High May degrade or might have a potential degradation
Unified Communications
Feb 18, 2026
FN74372
Action Required by March 31, 2026: Announcing Cisco Duo Certificate Authority Bundle Expiration
Software Upgrade Recommended
Critical May experience downtime or might be at risk of affecting services
Security
Feb 17, 2026
FN74367
Cisco Unified Communications Manager IM and Presence Rich Presence Based on Microsoft 365 Calendar Integration Will Not Get Updated
Software Upgrade Recommended
High May degrade or might have a potential degradation
Unified Communications
Feb 6, 2026
FN74374
Cisco BroadWorks CommPilot: Call Center Modification Failure and Session Termination in Release 2025.12_1.243
Software Upgrade Recommended
High May degrade or might have a potential degradation
Unified Communications
Feb 5, 2026
FN74373
Cisco Secure Client Zero Trust Access (ZTA) Agent – Potential Service Interruption Affecting Versions 5.1.8 - 5.1.12
Software Upgrade Recommended
High May degrade or might have a potential degradation
Security
Feb 3, 2026