Public vulnerability disclosure

CVE-2026-120982

Security Advisory 0207

publishedCWE-440

On affected platforms running Arista EOS with Border Gateway Protocol (BGP) configured, An unauthenticated attacker who can establish a BGP peering session with an affected device and can send specially crafted BGP messages to cause repeated BGP session resets, enabling sustained disruption to network routing and traffic forwarding.

Technical severity7.5 highCVSS 3.1 · CNA: Arista
Published2026-11-10Source updated 2026-11-13
Collected2026-11-133 attributed sources

Fixes and workarounds

Workaround

router bgp <asn> neighbor default received attribute discard 22 The above configuration applies the mitigation globally. The attribute can be re-enabled on specific peers if it is required within the customer application. For example: router bgp <asn> no neighbor X.X.X.X received attribute discard 22 Alternatively, a recommended mitigation to reduce exposure to this vulnerability is to configure BGP peer authentication using TCP-AO in order to ensure that only authorized peers can establish a BGP session.

Source: CNA: Arista

Affected products and versions

Affected products, source version ranges and reporting authorities
ProductVersionsAuthority
EOS
Arista Networks
Platforms: 710 Series, 720D Series, 720XP/722XPM Series, 750X Series, 7010TX Series, 7020R/R4 Series, 7130 Series running EOS, 7170 Series, 7050X3/X4 Series, 7060X/X2/X4/X5/X6/XE7 Series, 7260X/X3 Series, 7280R/R2/R3/R4 Series, 7300X/X3 Series, 7320X Series, 7358X4 Series, 7368X4 Series, 7388X5 Series, 7500R/R2/R3 Series, 7800R3/R4 Series, 7700R4 Series, AWE 5000 Series, AWE 7200R Series, ZTX-7200 Series, CloudEOS, cEOS-lab, vEOS-lab, CloudVision eXchange, virtual or physical appliance
≥ 4.36.0F; ≤ 4.36.2F (affected, custom)
≥ 4.35.0F; ≤ 4.35.6M (affected, custom)
≥ 4.34.0F; ≤ 4.34.8M (affected, custom)
≥ 4.33.0F; ≤ 4.33.10M (affected, custom)
≥ 1.0.0; < 4.33.0F (affected, custom)
Other versions: unaffected
CNA: Arista

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / scoreVectorAuthority
3.1 / 7.5
high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCNA: Arista
4.0 / 8.7
high
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NCNA: Arista
4.0 / 8.7
high
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XNVD: [email protected]
3.1 / 7.5
high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HNVD: [email protected]

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

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