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Cisco IOS XR on ASR 9000 Series Routers: Crafted IPv4 Packets Cause Line Card DoS (CVE-2026-76505)

1 fonte(s) · 1 atualização(ões) · publicado 21/10/2026 13:00 · coletado há 2 dias

Baseado só no resumo do feed. O site da fonte não liberou o texto completo para o Tifon, então esta análise saiu apenas do resumo publicado no feed e pode estar incompleta. Ela é atualizada quando outra fonte cobrir o assunto. Ler na fonte original ↗

Cisco disclosed CVE-2026-76505, a High-rated vulnerability in the IPv4 packet processing of Cisco IOS XR Software on Cisco ASR 9000 and 9900 Series routers and ASR 9902/9903 Compact High-Performance Routers. An unauthenticated, remote attacker can send crafted IPv4 packets that trigger network processor (NP) errors, resetting or shutting down a line card and causing a denial of service. Cisco has released software updates, and no workarounds exist. The article does not report active exploitation.

Detalhes técnicos

  • The flaw stems from incorrect handling of crafted IPv4 packets received on an affected line card interface and processed as for-us traffic (destined to the router itself).
  • The result is an NP reset and traffic loss on the affected line card while it recovers.
  • Under repeated reset conditions, the NP may enter a persistent shutdown state, requiring an explicit line card reload to restore traffic.
  • Transit IPv4 traffic does not trigger the issue, and IPv6 traffic cannot trigger it.

Remediação

  • Apply the Cisco software updates that fix this vulnerability, per the advisory cisco-sa-asr9k-tUyxcyXN.
  • No workarounds are available.

Linha do tempo

  1. sec.cloudapps.cisco.com ↗ · pub. 21/10/2026 13:00 · coletado 21/10 14:00 primeiro registro só resumo do feed

    Cisco IOS XR on ASR 9000 Series Routers: Crafted IPv4 Packets Cause Line Card DoS (CVE-2026-76505)

    ler a análise desta fonte

    Cisco disclosed CVE-2026-76505, a High-rated vulnerability in the IPv4 packet processing of Cisco IOS XR Software on Cisco ASR 9000 and 9900 Series routers and ASR 9902/9903 Compact High-Performance Routers. An unauthenticated, remote attacker can send crafted IPv4 packets that trigger network processor (NP) errors, resetting or shutting down a line card and causing a denial of service. Cisco has released software updates, and no workarounds exist. The article does not report active exploitation.

    Technical Details

    • The flaw stems from incorrect handling of crafted IPv4 packets received on an affected line card interface and processed as for-us traffic (destined to the router itself).
    • The result is an NP reset and traffic loss on the affected line card while it recovers.
    • Under repeated reset conditions, the NP may enter a persistent shutdown state, requiring an explicit line card reload to restore traffic.
    • Transit IPv4 traffic does not trigger the issue, and IPv6 traffic cannot trigger it.

    Remediation

    • Apply the Cisco software updates that fix this vulnerability, per the advisory cisco-sa-asr9k-tUyxcyXN.
    • No workarounds are available.