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CVE-2026-8170NVD status: Awaiting Analysis

Switch Engine (EXOS): Improper Link Resolution Before File Access

Published Updated By the CyberSecBulletin desk

CVE-2026-8170 is a high-severity improper link resolution before file access vulnerability in Switch Engine (EXOS) from Extreme Networks, with a CVSS 4.0 base score of 8.7 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 31.7.4, 32.7.4.15, 33.1.100 as the first without the flaw, so updating Switch Engine (EXOS) to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Switch Engine (EXOS) to 31.7.4 or 32.7.4.15 or 33.1.100 or 33.7.1, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
Extreme NetworksSwitch Engine (EXOS)before 31.7.4; 32.0.0 up to, but not including, 32.7.4.15; 33.0.0 up to, but not including, 33.1.100; 33.2.0 up to, but not including, 33.7.131.7.4, 32.7.4.15, 33.1.100, 33.7.1

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/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:X. Scored by CNA.

Official description

The mv, cp, and rm file utilities exposed within the ExtremeXOS (EXOS) shell environment fail to safely canonicalize paths and follow symbolic links outside of the intended privilege boundary. An attacker with low-privilege CLI access can create a symbolic link that references a privileged filesystem location and then invoke the affected utilities to read, modify, or replace security-critical files outside of their authorized scope. Under certain conditions, this may enable escalation to root-level access and persistent modification of the device software stack. Exploitation is possible remotely by an attacker holding a low-privilege account, or locally via the serial console. Extreme would like to thank Hadrien Barral (Université Gustave Eiffel) and Georges-Axel Jaloyan (French Ministry of the Interior) for responsible disclosure of their findings.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Link Resolution Before File Access

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

How developers prevent this class of flaw

  • Follow the principle of least privilege when assigning access rights to entities in a software system. Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

More Improper Link Resolution Before File Access vulnerabilities (CWE-59)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Switch Engine (EXOS)

All Switch Engine (EXOS) vulnerabilities

Recent Improper Link Resolution Before File Access vulnerabilities

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