CVE-2017-12319

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A vulnerability in the Border Gateway Protocol (BGP) over an Ethernet Virtual Private Network (EVPN) for Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload, resulting in a denial of service (DoS) condition, or potentially corrupt the BGP routing table, which could result in network instability. The vulnerability exists due to changes in the implementation of the BGP MPLS-Based Ethernet VPN RFC (RFC 7432) draft between IOS XE software releases. When the BGP Inclusive Multicast Ethernet Tag Route or BGP EVPN MAC/IP Advertisement Route update packet is received, it could be possible that the IP address length field is miscalculated. An attacker could exploit this vulnerability by sending a crafted BGP packet to an affected device after the BGP session was established. An exploit could allow the attacker to cause the affected device to reload or corrupt the BGP routing table; either outcome would result in a DoS. The vulnerability may be triggered when the router receives a crafted BGP message from a peer on an existing BGP session. This vulnerability affects all releases of Cisco IOS XE Software prior to software release 16.3 that support BGP EVPN configurations. If the device is not configured for EVPN, it is not vulnerable. Cisco Bug IDs: CSCui67191, CSCvg52875.

CVSS 5.9 (MEDIUM) KEV: KNOWN CATALOG

Attention and evidence

HYPE SCORE

0.0/10

REALITY · THREAT PRIORITY

7.9/10

General review priority; not probability

Evidence confidence: Exploitation recorded

Why this priority?

Recorded exploitation baseline: +7.00
Technical severity: CVSS 5.9: +0.89
Fresh EPSS: 5.24%: +0.03

General review priority, not probability, victim count or asset-specific risk. A range covers missing CVSS/EPSS inputs within the current evidence state.

Based on public data to date.

Hype components

Headline sample (25%)

0/100

Press, 30 days (60%)

0/100

Grounded branding (15%)

0/100

HYPE TOTAL0/100

Sources and documents

No source documents yet.

Score evolution

● Hype ● Reality

Earlier evidence-support scores are retained in history; this chart shows only the current priority definition.

First record: hype 0.0 · reality 7.9 (2026-11-02 15:12). The curve appears once the score changes.

Public exploit evidence

Public exploit entries / repo candidates

Evidence context and dated references

Reality is general threat/review priority, combining observed exploitation, CVSS severity and fresh EPSS. Evidence confidence is separate. This is not calibrated risk, a victim count or an asset-specific assessment. A range reflects missing numeric inputs.

Evidence in context

Confidence in exploitation evidence: Exploitation recorded
Priority basis: Recorded exploitation; CVSS 5.9; EPSS 5.2%
Attention, last 30 days: 0 distinct story titles; 0 press documents; 0 publisher domains.
Technical potential: network access, no prior privileges, no user interaction, additional attack conditions.
Observed activity: Exploitation recorded in CISA KEV.
Known scale: Not quantified.
Evidence confidence basis: Trusted exploitation confirmation

Score evaluated: 2026-11-05 13:57:48.666564+00:00 · EPSS snapshot: 2026-11-05T12:03:04Z

Source event timeline

Published

27 Mar 2018, 09:00

Added to the CISA KEV catalog

03 Mar 2022, 00:00

Score calculated

05 Nov 2026, 13:57