OOB Read in Cisco NX-OS (CWE-125)
CVE-2026-76457 Published on October 7, 2026
Cisco NX-OS Software Security Hardening Release: October 2026 - Out-of-bounds Read Vulnerabilities
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-2026-76457 are related to out-of-bounds read issues that are grouped under the Common Weakness Enumeration (CWE) CWE-125.
Vulnerability Analysis
CVE-2026-76457 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH
Weakness Type
Out-of-bounds Read
The software reads data past the end, or before the beginning, of the intended buffer. Typically, this can allow attackers to read sensitive information from other memory locations or cause a crash. A crash can occur when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string. The expected sentinel might not be located in the out-of-bounds memory, causing excessive data to be read, leading to a segmentation fault or a buffer overflow. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent read operation then produces undefined or unexpected results.
Products Associated with CVE-2026-76457
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Affected Versions
Cisco NX-OS Software:- Version 8.2(5) is affected.
- Version 7.3(5)D1(1) is affected.
- Version 8.4(2) is affected.
- Version 8.4(3) is affected.
- Version 9.2(3) is affected.
- Version 8.2(1) is affected.
- Version 7.3(1)D1(1) is affected.
- Version 9.2(2v) is affected.
- Version 7.3(0)D1(1) is affected.
- Version 7.3(4)D1(1) is affected.
- Version 9.2(1) is affected.
- Version 9.2(2t) is affected.
- Version 9.2(3y) is affected.
- Version 9.3(2) is affected.
- Version 7.3(1)DY(1) is affected.
- Version 8.1(1) is affected.
- Version 8.2(2) is affected.
- Version 8.3(2) is affected.
- Version 7.3(2)D1(3a) is affected.
- Version 9.2(4) is affected.
- Version 8.1(2) is affected.
- Version 7.3(3)D1(1) is affected.
- Version 8.2(3) is affected.
- Version 8.3(1) is affected.
- Version 8.4(1) is affected.
- Version 8.1(1b) is affected.
- Version 7.3(0)DX(1) is affected.
- Version 7.3(2)D1(1) is affected.
- Version 9.3(1) is affected.
- Version 7.3(2)D1(2) is affected.
- Version 8.2(4) is affected.
- Version 7.3(0)DY(1) is affected.
- Version 9.3(1z) is affected.
- Version 9.2(2) is affected.
- Version 8.1(2a) is affected.
- Version 7.3(2)D1(3) is affected.
- Version 8.1(1a) is affected.
- Version 8.4(1a) is affected.
- Version 9.3(3) is affected.
- Version 7.3(2)D1(1d) is affected.
- Version 9.3(4) is affected.
- Version 7.3(6)D1(1) is affected.
- Version 8.2(6) is affected.
- Version 9.3(5) is affected.
- Version 8.4(2a) is affected.
- Version 8.4(2b) is affected.
- Version 8.5(1) is affected.
- Version 9.3(6) is affected.
- Version 8.4(4) is affected.
- Version 7.3(7)D1(1) is affected.
- Version 8.4(2c) is affected.
- Version 9.3(5w) is affected.
- Version 8.2(7) is affected.
- Version 9.3(7) is affected.
- Version 9.3(7k) is affected.
- Version 7.3(8)D1(1) is affected.
- Version 9.3(7a) is affected.
- Version 8.2(7a) is affected.
- Version 9.3(8) is affected.
- Version 8.4(4a) is affected.
- Version 8.4(2d) is affected.
- Version 8.4(5) is affected.
- Version 8.2(8) is affected.
- Version 9.3(9) is affected.
- Version 7.3(9)D1(1) is affected.
- Version 8.4(6) is affected.
- Version 8.4(2e) is affected.
- Version 9.3(10) is affected.
- Version 9.2(1a) is affected.
- Version 8.2(9) is affected.
- Version 10.3(1) is affected.
- Version 8.4(7) is affected.
- Version 10.3(2) is affected.
- Version 8.4(6a) is affected.
- Version 9.3(11) is affected.
- Version 10.3(3) is affected.
- Version 9.4(1) is affected.
- Version 9.3(2a) is affected.
- Version 8.4(2f) is affected.
- Version 8.2(10) is affected.
- Version 9.3(12) is affected.
- Version 10.4(1) is affected.
- Version 8.4(8) is affected.
- Version 10.3(99w) is affected.
- Version 10.3(3w) is affected.
- Version 10.3(99x) is affected.
- Version 10.3(3o) is affected.
- Version 8.4(9) is affected.
- Version 10.3(4) is affected.
- Version 10.3(3p) is affected.
- Version 10.3(4a) is affected.
- Version 9.4(1a) is affected.
- Version 10.4(2) is affected.
- Version 10.3(3q) is affected.
- Version 9.3(13) is affected.
- Version 8.2(11) is affected.
- Version 9.4(2) is affected.
- Version 10.3(5) is affected.
- Version 10.4(3) is affected.
- Version 10.3(3x) is affected.
- Version 10.3(4g) is affected.
- Version 10.5(1) is affected.
- Version 8.4(10) is affected.
- Version 9.4(2a) is affected.
- Version 10.3(3r) is affected.
- Version 10.3(6) is affected.
- Version 9.3(14) is affected.
- Version 10.4(4) is affected.
- Version 10.3(4h) is affected.
- Version 10.5(2) is affected.
- Version 10.5(1j) is affected.
- Version 8.4(11) is affected.
- Version 9.4(3) is affected.
- Version 10.3(7) is affected.
- Version 10.4(5) is affected.
- Version 10.5(3) is affected.
- Version 9.3(15) is affected.
- Version 9.4(3a) is affected.
- Version 10.4(4g) is affected.
- Version 10.5(4) is affected.
- Version 9.4(3b) is affected.
- Version 8.4(12) is affected.
- Version 10.6(1) is affected.
- Version 10.5(3t) is affected.
- Version 10.3(8) is affected.
- Version 10.4(6) is affected.
- Version 10.5(3s) is affected.
- Version 10.5(3e) is affected.
- Version 9.4(4) is affected.
- Version 10.5(3o) is affected.
- Version 9.3(16) is affected.
- Version 10.6(1s) is affected.
- Version 10.6(2) is affected.
- Version 10.5(3p) is affected.
- Version 9.4(5) is affected.
- Version 10.3(9) is affected.
- Version 10.6(2s) is affected.
- Version 8.4(13) is affected.
- Version 10.6(3) is affected.
- Version 10.4(7) is affected.
- Version 10.5(5) is affected.
- Version 9.3(17) is affected.
- Version 10.6(2n) is affected.
- Version 10.6(3q) is affected.
- Version 10.6(3o) is affected.
- Version 10.6(3s) is affected.
- Version 15.2(1g) is affected.
- Version 15.2(2e) is affected.
- Version 15.2(2f) is affected.
- Version 15.2(2g) is affected.
- Version 15.2(2h) is affected.
- Version 15.2(3f) is affected.
- Version 15.2(3e) is affected.
- Version 15.2(3g) is affected.
- Version 15.2(4d) is affected.
- Version 15.2(4e) is affected.
- Version 15.2(5c) is affected.
- Version 15.2(5d) is affected.
- Version 16.0(1g) is affected.
- Version 15.2(5e) is affected.
- Version 15.2(4f) is affected.
- Version 15.2(6e) is affected.
- Version 15.2(6h) is affected.
- Version 16.0(1j) is affected.
- Version 15.2(6g) is affected.
- Version 15.2(7f) is affected.
- Version 15.2(7g) is affected.
- Version 16.0(2h) is affected.
- Version 15.2(8d) is affected.
- Version 16.0(2j) is affected.
- Version 15.2(8e) is affected.
- Version 16.0(3d) is affected.
- Version 16.0(3e) is affected.
- Version 15.2(8f) is affected.
- Version 15.2(8g) is affected.
- Version 15.3(1d) is affected.
- Version 15.2(8h) is affected.
- Version 16.0(4c) is affected.
- Version 15.3(2a) is affected.
- Version 15.2(8i) is affected.
- Version 16.0(5h) is affected.
- Version 15.3(2b) is affected.
- Version 16.0(3g) is affected.
- Version 16.0(5j) is affected.
- Version 15.3(2c) is affected.
- Version 16.0(6c) is affected.
- Version 15.3(2d) is affected.
- Version 16.1(1f) is affected.
- Version 16.0(7e) is affected.
- Version 16.0(8e) is affected.
- Version 15.3(2e) is affected.
- Version 16.0(8f) is affected.
- Version 16.1(2f) is affected.
- Version 16.1(2g) is affected.
- Version 15.3(2f) is affected.
- Version 16.0(9c) is affected.
- Version 16.1(3f) is affected.
- Version 16.0(9d) is affected.
- Version 16.0(6h) is affected.
- Version 16.0(8h) is affected.
- Version 16.1(3g) is affected.
- Version 16.0(9e) is affected.
- Version 16.1(4h) is affected.
- Version 16.1(5e) is affected.
- Version 16.2(1g) is affected.
- Version 16.0(9f) is affected.
- Version 16.2(2e) is affected.
- Version 4.0(1a) is affected.
- Version 4.1(1d) is affected.
- Version 4.0(4f) is affected.
- Version 4.0(4c) is affected.
- Version 4.0(2b) is affected.
- Version 4.1(2a) is affected.
- Version 4.0(4a) is affected.
- Version 4.0(4e) is affected.
- Version 4.0(4h) is affected.
- Version 4.0(2a) is affected.
- Version 4.1(1c) is affected.
- Version 4.0(1b) is affected.
- Version 4.1(1e) is affected.
- Version 4.0(4d) is affected.
- Version 4.0(4b) is affected.
- Version 4.0(2e) is affected.
- Version 4.1(1a) is affected.
- Version 4.0(4g) is affected.
- Version 4.0(1d) is affected.
- Version 4.0(1c) is affected.
- Version 4.0(4i) is affected.
- Version 4.0(2d) is affected.
- Version 4.1(1b) is affected.
- Version 4.1(2b) is affected.
- Version 4.0(4k) is affected.
- Version 4.1(3a) is affected.
- Version 4.1(3b) is affected.
- Version 4.1(2c) is affected.
- Version 4.0(4l) is affected.
- Version 4.1(4a) is affected.
- Version 4.1(3c) is affected.
- Version 4.1(3d) is affected.
- Version 4.2(1c) is affected.
- Version 4.2(1d) is affected.
- Version 4.0(4m) is affected.
- Version 4.1(3e) is affected.
- Version 4.2(1f) is affected.
- Version 4.1(3f) is affected.
- Version 4.2(1i) is affected.
- Version 4.1(3h) is affected.
- Version 4.2(1k) is affected.
- Version 4.2(1l) is affected.
- Version 4.0(4n) is affected.
- Version 4.2(1m) is affected.
- Version 4.1(3i) is affected.
- Version 4.2(2a) is affected.
- Version 4.2(1n) is affected.
- Version 4.1(3j) is affected.
- Version 4.2(2c) is affected.
- Version 4.2(2d) is affected.
- Version 4.2(3b) is affected.
- Version 4.1(3k) is affected.
- Version 4.0(4o) is affected.
- Version 4.2(2e) is affected.
- Version 4.2(3d) is affected.
- Version 4.2(3e) is affected.
- Version 4.2(3g) is affected.
- Version 4.1(3l) is affected.
- Version 4.3(2b) is affected.
- Version 4.2(3h) is affected.
- Version 4.2(3i) is affected.
- Version 4.3(2c) is affected.
- Version 4.1(3m) is affected.
- Version 4.3(2e) is affected.
- Version 4.3(3a) is affected.
- Version 4.2(3j) is affected.
- Version 4.3(3c) is affected.
- Version 4.3(4a) is affected.
- Version 4.2(3k) is affected.
- Version 4.3(4b) is affected.
- Version 4.3(4c) is affected.
- Version 4.2(3l) is affected.
- Version 4.3(4d) is affected.
- Version 4.3(2f) is affected.
- Version 4.2(3m) is affected.
- Version 4.3(5a) is affected.
- Version 4.3(4e) is affected.
- Version 4.1(3n) is affected.
- Version 4.3(4f) is affected.
- Version 4.2(3n) is affected.
- Version 4.3(5c) is affected.
- Version 4.2(3o) is affected.
- Version 4.3(5d) is affected.
- Version 4.3(6a) is affected.
- Version 4.3(6b) is affected.
- Version 4.3(5e) is affected.
- Version 4.3(6c) is affected.
- Version 4.2(3p) is affected.
- Version 6.0(1b) is affected.
- Version 6.0(1c) is affected.
- Version 4.3(6d) is affected.
- Version 6.0(1d) is affected.
- Version 6.0(1e) is affected.
- Version 4.3(6e) is affected.
- Version 6.0(1f) is affected.
- Version 4.3(6f) is affected.
- Version 6.0(2b) is affected.
- Version 6.0(1h) is affected.
- Version 4.2(3r) is affected.
- Version 6.0(2c) is affected.
- Version 4.3(6g) is affected.
- Version 6.0(2d) is affected.
- Version 4.3(6h) is affected.
- Version 4.2(3s) is affected.
- Version 4.3(6i) is affected.