9.8

CVE-2026-76459: cisco cisco nx-os software Out-of-bounds Write

CVSS: 9.8v3.1CriticalAwaiting analysis
Published 07-10-2026Last modified 09-10-2026
Open JSON

Vulnerability summary

CVE-2026-76459 is a critical (CVSS 9.8) Out-of-bounds Write vulnerability in cisco cisco nx-os software. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 21.9% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.31%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 07-10-2026
    PublishedVulnerability first disclosed.
  2. 09-10-2026
    Last modifiedVulnerability information updated.

Description

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco NX-OS engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-76459 are related to out-of-bounds write issues that are grouped under the Common Weakness Enumeration (CWE) CWE-787.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.31%

Chance of exploitation in the next 30 days

Percentile

22%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

08-10-202618-10-2026
EPSS score
0.31%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Cisco3 products
  • cisco nx-os software8.2(5) | 7.3(5)D1(1) | 8.4(2) | 8.4(3) | 9.2(3) | 8.2(1) | 7.3(1)D1(1) | 9.2(2v) | 7.3(0)D1(1) | 7.3(4)D1(1) | 9.2(1) | 9.2(2t) | 9.2(3y) | 9.3(2) | 7.3(1)DY(1) | 8.1(1) | 8.2(2) | 8.3(2) | 7.3(2)D1(3a) | 9.2(4) | 8.1(2) | 7.3(3)D1(1) | 8.2(3) | 8.3(1) | 8.4(1) | 8.1(1b) | 7.3(0)DX(1) | 7.3(2)D1(1) | 9.3(1) | 7.3(2)D1(2) | 8.2(4) | 7.3(0)DY(1) | 9.3(1z) | 9.2(2) | 8.1(2a) | 7.3(2)D1(3) | 8.1(1a) | 8.4(1a) | 9.3(3) | 7.3(2)D1(1d) | 9.3(4) | 7.3(6)D1(1) | 8.2(6) | 9.3(5) | 8.4(2a) | 8.4(2b) | 8.5(1) | 9.3(6) | 8.4(4) | 7.3(7)D1(1) | 8.4(2c) | 9.3(5w) | 8.2(7) | 9.3(7) | 9.3(7k) | 7.3(8)D1(1) | 9.3(7a) | 8.2(7a) | 9.3(8) | 8.4(4a) | 8.4(2d) | 8.4(5) | 8.2(8) | 9.3(9) | 7.3(9)D1(1) | 8.4(6) | 8.4(2e) | 9.3(10) | 9.2(1a) | 8.2(9) | 10.3(1) | 8.4(7) | 10.3(2) | 8.4(6a) | 9.3(11) | 10.3(3) | 9.4(1) | 9.3(2a) | 8.4(2f) | 8.2(10) | 9.3(12) | 10.4(1) | 8.4(8) | 10.3(99w) | 10.3(3w) | 10.3(99x) | 10.3(3o) | 8.4(9) | 10.3(4) | 10.3(3p) | 10.3(4a) | 9.4(1a) | 10.4(2) | 10.3(3q) | 9.3(13) | 8.2(11) | 9.4(2) | 10.3(5) | 10.4(3) | 10.3(3x) | 10.3(4g) | 10.5(1) | 8.4(10) | 9.4(2a) | 10.3(3r) | 10.3(6) | 9.3(14) | 10.4(4) | 10.3(4h) | 10.5(2) | 10.5(1j) | 8.4(11) | 9.4(3) | 10.3(7) | 10.4(5) | 10.5(3) | 9.3(15) | 9.4(3a) | 10.4(4g) | 10.5(4) | 9.4(3b) | 8.4(12) | 10.6(1) | 10.5(3t) | 10.3(8) | 10.4(6) | 10.5(3s) | 10.5(3e) | 9.4(4) | 10.5(3o) | 9.3(16) | 10.6(1s) | 10.6(2) | 10.5(3p) | 9.4(5) | 10.3(9) | 10.6(2s) | 8.4(13) | 10.6(3) | 10.4(7) | 10.5(5) | 9.3(17) | 10.6(2n) | 10.6(3q) | 10.6(3o) | 10.6(3s)
  • cisco nx-os system software in aci mode15.2(1g) | 15.2(2e) | 15.2(2f) | 15.2(2g) | 15.2(2h) | 15.2(3f) | 15.2(3e) | 15.2(3g) | 15.2(4d) | 15.2(4e) | 15.2(5c) | 15.2(5d) | 16.0(1g) | 15.2(5e) | 15.2(4f) | 15.2(6e) | 15.2(6h) | 16.0(1j) | 15.2(6g) | 15.2(7f) | 15.2(7g) | 16.0(2h) | 15.2(8d) | 16.0(2j) | 15.2(8e) | 16.0(3d) | 16.0(3e) | 15.2(8f) | 15.2(8g) | 15.3(1d) | 15.2(8h) | 16.0(4c) | 15.3(2a) | 15.2(8i) | 16.0(5h) | 15.3(2b) | 16.0(3g) | 16.0(5j) | 15.3(2c) | 16.0(6c) | 15.3(2d) | 16.1(1f) | 16.0(7e) | 16.0(8e) | 15.3(2e) | 16.0(8f) | 16.1(2f) | 16.1(2g) | 15.3(2f) | 16.0(9c) | 16.1(3f) | 16.0(9d) | 16.0(6h) | 16.0(8h) | 16.1(3g) | 16.0(9e) | 16.1(4h) | 16.1(5e) | 16.2(1g) | 16.0(9f) | 16.2(2e)
  • cisco unified computing system (managed)4.0(1a) | 4.1(1d) | 4.0(4f) | 4.0(4c) | 4.0(2b) | 4.1(2a) | 4.0(4a) | 4.0(4e) | 4.0(4h) | 4.0(2a) | 4.1(1c) | 4.0(1b) | 4.1(1e) | 4.0(4d) | 4.0(4b) | 4.0(2e) | 4.1(1a) | 4.0(4g) | 4.0(1d) | 4.0(1c) | 4.0(4i) | 4.0(2d) | 4.1(1b) | 4.1(2b) | 4.0(4k) | 4.1(3a) | 4.1(3b) | 4.1(2c) | 4.0(4l) | 4.1(4a) | 4.1(3c) | 4.1(3d) | 4.2(1c) | 4.2(1d) | 4.0(4m) | 4.1(3e) | 4.2(1f) | 4.1(3f) | 4.2(1i) | 4.1(3h) | 4.2(1k) | 4.2(1l) | 4.0(4n) | 4.2(1m) | 4.1(3i) | 4.2(2a) | 4.2(1n) | 4.1(3j) | 4.2(2c) | 4.2(2d) | 4.2(3b) | 4.1(3k) | 4.0(4o) | 4.2(2e) | 4.2(3d) | 4.2(3e) | 4.2(3g) | 4.1(3l) | 4.3(2b) | 4.2(3h) | 4.2(3i) | 4.3(2c) | 4.1(3m) | 4.3(2e) | 4.3(3a) | 4.2(3j) | 4.3(3c) | 4.3(4a) | 4.2(3k) | 4.3(4b) | 4.3(4c) | 4.2(3l) | 4.3(4d) | 4.3(2f) | 4.2(3m) | 4.3(5a) | 4.3(4e) | 4.1(3n) | 4.3(4f) | 4.2(3n) | 4.3(5c) | 4.2(3o) | 4.3(5d) | 4.3(6a) | 4.3(6b) | 4.3(5e) | 4.3(6c) | 4.2(3p) | 6.0(1b) | 6.0(1c) | 4.3(6d) | 6.0(1d) | 6.0(1e) | 4.3(6e) | 6.0(1f) | 4.3(6f) | 6.0(2b) | 6.0(1h) | 4.2(3r) | 6.0(2c) | 4.3(6g) | 6.0(2d) | 4.3(6h) | 4.2(3s) | 4.3(6i)

1 vendor · 3 products

References

1 links