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CVE-2023-20080

Cisco IOS and IOS XE Software IPv6 DHCP (DHCPv6) Relay and Server Denial of Service Vulnerability

HIGH

7.5

CVSS Score

Published: March 23, 2023 at 12:00 AM UTC

Updated: June 17, 2026 at 05:29 AM UTC

2 products affected across 1 vendorIOSIOS Xe

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Severity

HIGH7.5

Exploit prediction

EPSS 1.0%

SSVC

No known exploit

Description

A vulnerability in the IPv6 DHCP version 6 (DHCPv6) relay and server features of Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition. This vulnerability is due to insufficient validation of data boundaries. An attacker could exploit this vulnerability by sending crafted DHCPv6 messages to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

IOS · Cisconpm

95%

12.2(6)i1 15.1(2)sg 15.1(2)sg1 15.1(2)sg2 15.1(2)sg3 15.1(2)sg4 15.1(2)sg5 15.1(2)sg6 15.1(2)sg7 15.1(2)sg8 15.1(2)sy1 15.1(2)sy1015.1(2)sy1115.1(2)sy1215.1(2)sy1315.1(2)sy1415.1(2)sy1515.1(2)sy1615.1(2)sy16a 15.1(2)sy2 15.1(2)sy3 15.1(2)sy4 15.1(2)sy4a 15.1(2)sy5 15.1(2)sy6 15.1(2)sy7 15.1(2)sy8 15.1(2)sy9 15.1(3)svr10 15.1(3)svs 15.1(3)svt1 15.1(3)svt3 15.1(3)svt4 15.1(3)svu1 15.1(3)svu10 15.1(3)svu11 15.1(3)svu2 15.1(3)svu20 15.1(3)svu21 15.1(3)svv1 15.1(3)svv2 15.1(3)svv3 15.1(3)svw 15.1(3)svw1 15.1(3)svx 15.1(3)svx1 15.1(4)m10 15.1(4)m12a 15.1(4)m7 15.1(4)m8 15.1(4)m9 15.2(1)e 15.2(1)e1 15.2(1)e2 15.2(1)e3 15.2(1)ey 15.2(1)s 15.2(1)s1 15.2(1)s2 15.2(1)sy 15.2(1)sy0a 15.2(1)sy1 15.2(1)sy1a 15.2(1)sy2 15.2(1)sy3 15.2(1)sy415.2(1)sy515.2(1)sy615.2(1)sy715.2(1)sy815.2(2)e 15.2(2)e1 15.2(2)e10 15.2(2)e10a 15.2(2)e10b 15.2(2)e2 15.2(2)e3 15.2(2)e4 15.2(2)e5 15.2(2)e5a 15.2(2)e5b 15.2(2)e6 15.2(2)e7 15.2(2)e7b 15.2(2)e8 15.2(2)e9 15.2(2)e9a 15.2(2)ea 15.2(2)ea1 15.2(2)ea2 15.2(2)ea3 15.2(2)eb 15.2(2)eb1 15.2(2)eb2 15.2(2)s 15.2(2)s0a 15.2(2)s0c 15.2(2)s0d 15.2(2)s1 15.2(2)s2 15.2(2)sc1 15.2(2)sc3 15.2(2)sc4 15.2(2)sy 15.2(2)sy1 15.2(2)sy215.2(2)sy315.2(234k)e 15.2(2a)e1 15.2(2a)e2 15.2(2b)e 15.2(3)e 15.2(3)e1 15.2(3)e2 15.2(3)e3 15.2(3)e4 15.2(3)e5 15.2(3)ea 15.2(3a)e 15.2(3m)e2 15.2(3m)e7 15.2(3m)e8 15.2(4)e 15.2(4)e1 15.2(4)e10 15.2(4)e10a 15.2(4)e10b 15.2(4)e10c 15.2(4)e2 15.2(4)e3 15.2(4)e4 15.2(4)e5 15.2(4)e5a 15.2(4)e6 15.2(4)e7 15.2(4)e8 15.2(4)e9 15.2(4)ea 15.2(4)ea1 15.2(4)ea2 15.2(4)ea3 15.2(4)ea4 15.2(4)ea5 15.2(4)ea6 15.2(4)ea7 15.2(4)ea8 15.2(4)ea9 15.2(4)ea9a 15.2(4)ec1 15.2(4)ec2 15.2(4)gc1 15.2(4)gc2 15.2(4)gc3 15.2(4)m10 15.2(4)m11 15.2(4)m5 15.2(4)m6 15.2(4)m6a 15.2(4)m6b 15.2(4)m7 15.2(4)m8 15.2(4)m9 15.2(4)s 15.2(4)s0c 15.2(4)s1 15.2(4)s1c 15.2(4)s2 15.2(4)s3 15.2(4)s3a 15.2(4)s4 15.2(4)s4a 15.2(4)s5 15.2(4)s6 15.2(4)s7 15.2(4)s8 15.2(4m)e1 15.2(4m)e2 15.2(4m)e3 15.2(4n)e2 15.2(4o)e2 15.2(4o)e3 15.2(4p)e1 15.2(4q)e1 15.2(4s)e1 15.2(5)e 15.2(5)e115.2(5)e215.2(5)e2b 15.2(5)e2c 15.2(5)ea 15.2(5)ex 15.2(5a)e 15.2(5a)e1 15.2(5b)e 15.2(5c)e 15.2(6)e 15.2(6)e0a15.2(6)e0c15.2(6)e1 15.2(6)e1a 15.2(6)e1s 15.2(6)e2 15.2(6)e2a 15.2(6)e2b 15.2(6)e3 15.2(6)eb 15.2(7)e 15.2(7)e0a 15.2(7)e0b 15.2(7)e0s 15.2(7)e1 15.2(7)e1a 15.2(7)e2 15.2(7)e2a 15.2(7)e2b 15.2(7)e3 15.2(7)e3a 15.2(7)e3k 15.2(7)e4 15.2(7)e5 15.2(7)e615.2(7a)e0b15.2(7b)e0b15.2(8)e 15.2(8)e1 15.2(8)e2 15.3(0)sy 15.3(1)s 15.3(1)s1 15.3(1)s1e 15.3(1)s2 15.3(1)sy 15.3(1)sy1 15.3(1)sy2 15.3(2)s 15.3(2)s1 15.3(2)s2 15.3(2)t1 15.3(2)t2 15.3(2)t3 15.3(2)t4 15.3(3)s 15.3(3)s1 15.3(3)s10 15.3(3)s1a 15.3(3)s2 15.3(3)s2a 15.3(3)s3 15.3(3)s4 15.3(3)s5 15.3(3)s6 15.3(3)s6a 15.3(3)s7 15.3(3)s8 15.3(3)s8a 15.3(3)s9 15.4(1)cg 15.4(1)cg1 15.4(1)s 15.4(1)s1 15.4(1)s2 15.4(1)s3 15.4(1)s4 15.4(1)sy 15.4(1)sy1 15.4(1)sy215.4(1)sy315.4(1)sy415.4(1)t 15.4(1)t1 15.4(1)t2 15.4(1)t3 15.4(1)t4 15.4(2)cg 15.4(2)s 15.4(2)s1 15.4(2)s2 15.4(2)s3 15.4(2)s4 15.4(2)sn 15.4(2)sn1 15.4(2)t 15.4(2)t1 15.4(2)t2 15.4(2)t3 15.4(2)t4 15.4(3)m 15.4(3)m1 15.4(3)m10 15.4(3)m2 15.4(3)m3 15.4(3)m4 15.4(3)m5 15.4(3)m6 15.4(3)m6a 15.4(3)m7 15.4(3)m7a 15.4(3)m8 15.4(3)m9 15.4(3)s 15.4(3)s0d 15.4(3)s0e 15.4(3)s0f 15.4(3)s1 15.4(3)s10 15.4(3)s2 15.4(3)s3 15.4(3)s4 15.4(3)s5 15.4(3)s6 15.4(3)s6a 15.4(3)s7 15.4(3)s8 15.4(3)s9 15.4(3)sn1 15.4(3)sn1a 15.5(1)s 15.5(1)s1 15.5(1)s2 15.5(1)s3 15.5(1)s4 15.5(1)sn 15.5(1)sn1 15.5(1)sy 15.5(1)sy115.5(1)sy215.5(1)sy315.5(1)sy415.5(1)sy515.5(1)sy615.5(1)sy715.5(1)sy815.5(1)sy915.5(1)t 15.5(1)t1 15.5(1)t2 15.5(1)t3 15.5(1)t4 15.5(2)s 15.5(2)s1 15.5(2)s2 15.5(2)s3 15.5(2)s4 15.5(2)sn 15.5(2)t 15.5(2)t1 15.5(2)t2 15.5(2)t3 15.5(2)t4 15.5(2)xb 15.5(3)m 15.5(3)m0a 15.5(3)m1 15.5(3)m10 15.5(3)m11 15.5(3)m11a 15.5(3)m2 15.5(3)m2a 15.5(3)m3 15.5(3)m4 15.5(3)m4a 15.5(3)m4b 15.5(3)m4c 15.5(3)m5 15.5(3)m6 15.5(3)m6a 15.5(3)m7 15.5(3)m8 15.5(3)m9 15.5(3)s 15.5(3)s0a 15.5(3)s1 15.5(3)s10 15.5(3)s10a 15.5(3)s10b 15.5(3)s1a 15.5(3)s2 15.5(3)s3 15.5(3)s4 15.5(3)s5 15.5(3)s6 15.5(3)s6a 15.5(3)s6b 15.5(3)s7 15.5(3)s8 15.5(3)s9 15.5(3)s9a 15.5(3)sn 15.5(3)sn0a 15.6(1)s 15.6(1)s1 15.6(1)s2 15.6(1)s3 15.6(1)s4 15.6(1)sn 15.6(1)sn1 15.6(1)sn2 15.6(1)sn3 15.6(1)t 15.6(1)t0a 15.6(1)t1 15.6(1)t2 15.6(1)t3 15.6(2)s 15.6(2)s1 15.6(2)s2 15.6(2)s3 15.6(2)s4 15.6(2)sn 15.6(2)sp 15.6(2)sp1 15.6(2)sp2 15.6(2)sp3 15.6(2)sp4 15.6(2)sp5 15.6(2)sp6 15.6(2)sp7 15.6(2)sp8 15.6(2)sp8a 15.6(2)sp9 15.6(2)t 15.6(2)t0a 15.6(2)t1 15.6(2)t2 15.6(2)t3 15.6(3)m 15.6(3)m0a 15.6(3)m1 15.6(3)m1a 15.6(3)m1b 15.6(3)m2 15.6(3)m2a 15.6(3)m3 15.6(3)m3a 15.6(3)m4 15.6(3)m5 15.6(3)m6 15.6(3)m6a 15.6(3)m6b 15.6(3)m7 15.6(3)m8 15.6(3)m9 15.6(3)sn 15.6(4)sn 15.6(5)sn 15.6(7)sn 15.6(7)sn1 15.6(7)sn2 15.7(3)m 15.7(3)m0a 15.7(3)m1 15.7(3)m2 15.7(3)m3 15.7(3)m4 15.7(3)m4a 15.7(3)m4b 15.7(3)m5 15.7(3)m6 15.7(3)m7 15.7(3)m8 15.7(3)m9 15.8(3)m 15.8(3)m0a 15.8(3)m0b 15.8(3)m1 15.8(3)m1a 15.8(3)m2 15.8(3)m2a 15.8(3)m3 15.8(3)m3a 15.8(3)m3b 15.8(3)m4 15.8(3)m5 15.8(3)m6 15.8(3)m7 15.8(3)m8 15.9(3)m 15.9(3)m0a 15.9(3)m1 15.9(3)m2 15.9(3)m2a 15.9(3)m3 15.9(3)m3a 15.9(3)m3b 15.9(3)m4 15.9(3)m4a 15.9(3)m5

IOS Xe · Cisco

95%

16.1.1 16.1.2 16.1.3 16.10.1 16.10.1a 16.10.1b 16.10.1c 16.10.1d 16.10.1e 16.10.1f 16.10.1g 16.10.1s 16.10.2 16.10.3 16.11.1 16.11.1a 16.11.1b 16.11.1c 16.11.1s 16.11.2 16.12.1 16.12.1a 16.12.1c 16.12.1s 16.12.1t 16.12.1w 16.12.1x 16.12.1y 16.12.1z 16.12.1z1 16.12.1z2 16.12.2 16.12.2a 16.12.2s 16.12.2t 16.12.3 16.12.3a 16.12.3s 16.12.4 16.12.4a 16.12.5 16.12.5a 16.12.5b 16.12.6 16.12.6a 16.12.7 16.2.1 16.2.2 16.3.1 16.3.10 16.3.11 16.3.1a 16.3.2 16.3.3 16.3.4 16.3.5 16.3.5b 16.3.6 16.3.7 16.3.8 16.3.9 16.4.1 16.4.2 16.4.3 16.5.1 16.5.1a 16.5.1b 16.5.2 16.5.3 16.6.1 16.6.10 16.6.2 16.6.3 16.6.4 16.6.4a 16.6.4s 16.6.5 16.6.5a 16.6.5b 16.6.6 16.6.7 16.6.7a 16.6.8 16.6.9 16.7.1 16.7.1a 16.7.1b 16.7.2 16.7.3 16.7.4 16.8.1 16.8.1a 16.8.1b 16.8.1c 16.8.1d 16.8.1e 16.8.1s 16.8.2 16.8.3 16.9.1 16.9.1a 16.9.1b 16.9.1c 16.9.1d 16.9.1s 16.9.2 16.9.2a 16.9.2s 16.9.3 16.9.3a 16.9.3h 16.9.3s 16.9.4 16.9.4c 16.9.5 16.9.5f 16.9.6 16.9.7 16.9.8 16.9.8a 16.9.8b 17.1.1 17.1.1a 17.1.1s 17.1.1t 17.1.2 17.1.3 17.2.1 17.2.1a 17.2.1r 17.2.1v 17.2.2 17.2.3 17.3.1 17.3.1a 17.3.1w 17.3.1x 17.3.1z 17.3.2 17.3.2a 17.3.3 17.3.3a 17.4.1 17.4.1a 17.4.1b 17.4.1c 17.4.2 17.4.2a 3.10.0ce 3.10.0e 3.10.0s 3.10.10s 3.10.1ae 3.10.1e 3.10.1s 3.10.1se 3.10.1xbs 3.10.1xcs 3.10.2as 3.10.2e 3.10.2s 3.10.2ts 3.10.3e 3.10.3s 3.10.4s 3.10.5s 3.10.6s 3.10.7s 3.10.8as 3.10.8s 3.10.9s 3.11.0e 3.11.0s 3.11.1ae 3.11.1e 3.11.1s 3.11.2ae 3.11.2e 3.11.2s 3.11.3ae 3.11.3e 3.11.3s 3.11.4e 3.11.4s 3.11.5e 3.11.6e 3.12.0as 3.12.0s 3.12.1s 3.12.2s 3.12.3s 3.12.4s 3.13.0as 3.13.0s 3.13.10s 3.13.1s 3.13.2as 3.13.2s 3.13.3s 3.13.4s 3.13.5as 3.13.5s 3.13.6as 3.13.6bs 3.13.6s 3.13.7as 3.13.7s 3.13.8s 3.13.9s 3.14.0s 3.14.1s 3.14.2s 3.14.3s 3.14.4s 3.15.0s 3.15.1cs 3.15.1s 3.15.2s 3.15.3s 3.15.4s 3.16.0as 3.16.0bs 3.16.0cs 3.16.0s 3.16.10as 3.16.10bs 3.16.10s 3.16.1as 3.16.1s 3.16.2as 3.16.2bs 3.16.2s 3.16.3as 3.16.3s 3.16.4as 3.16.4bs 3.16.4cs 3.16.4ds 3.16.4es 3.16.4gs 3.16.4s 3.16.5as 3.16.5bs 3.16.5s 3.16.6bs 3.16.6s 3.16.7as 3.16.7bs 3.16.7s 3.16.8s 3.16.9s 3.17.0s 3.17.1as 3.17.1s 3.17.2s 3.17.3s 3.17.4s 3.18.0as 3.18.0s 3.18.0sp 3.18.1asp 3.18.1bsp 3.18.1csp 3.18.1gsp 3.18.1hsp 3.18.1isp 3.18.1s 3.18.1sp 3.18.2asp 3.18.2s 3.18.2sp 3.18.3asp 3.18.3bsp 3.18.3s 3.18.3sp 3.18.4s 3.18.4sp 3.18.5sp 3.18.6sp 3.18.7sp 3.18.8asp 3.18.8sp 3.18.9sp 3.3.0xo 3.3.1xo 3.3.2xo 3.4.0sg 3.4.1sg 3.4.2sg 3.4.3sg 3.4.4sg 3.4.5sg 3.4.6sg 3.4.7sg 3.4.8sg 3.5.0e 3.5.1e 3.5.2e 3.5.3e 3.6.0ae 3.6.0be 3.6.0e 3.6.10e 3.6.1e 3.6.2ae 3.6.2e 3.6.3e 3.6.4e 3.6.5ae 3.6.5be 3.6.5e 3.6.6e 3.6.7ae 3.6.7be 3.6.7e 3.6.8e 3.6.9ae 3.6.9e 3.7.0bs 3.7.0e 3.7.0s 3.7.0xas 3.7.0xbs 3.7.1as 3.7.1e 3.7.1s 3.7.2e 3.7.2s 3.7.2ts 3.7.3e 3.7.3s 3.7.4as 3.7.4e 3.7.4s 3.7.5e 3.7.5s 3.7.6s 3.7.7s 3.7.8s 3.8.0e 3.8.0s 3.8.10ce 3.8.10e 3.8.1e 3.8.1s 3.8.2e 3.8.2s 3.8.3e 3.8.4e 3.8.5ae 3.8.5e 3.8.6e 3.8.7e 3.8.8e 3.8.9e 3.9.0as 3.9.0e 3.9.0s 3.9.0xas 3.9.1as 3.9.1e 3.9.1s 3.9.2be3.9.2e3.9.2s

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-dhcpv6-dos-44cMvdDK

References (1)

Vendor Advisory

Source: [email protected]

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-dhcpv6-dos-44cMvdDK

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGH[email protected]

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-129

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