CVE-2026-118485 Axel Download Accelerator CVE debrief

Who should care

Defenders and administrators responsible for systems using Axel Download Accelerator should assess exposure and prioritize verification and mitigation to prevent potential attacks. This includes verifying the integrity of downloaded content and filesystem paths, preventing potential attacks by restricting access to the download accelerator, and monitoring for suspicious activity and implementing compensating controls.

Why it matters

CVE-2026-118485 is a high-severity vulnerability in Axel Download Accelerator that allows attackers to write to arbitrary filesystem paths. Defenders should prioritize verification and mitigation to prevent potential attacks.

• Verify the integrity of downloaded content and filesystem paths.
• Prevent potential attacks by restricting access to the download accelerator.
• Monitor for suspicious activity and implement compensating controls.

Technical summary

The vulnerability is caused by the URL percent-decoding feature in Axel Download Accelerator, which allows an attacker to embed directory traversal sequences in the URL path. This can cause the download accelerator to write downloaded content to arbitrary filesystem paths relative to the current working directory. The vulnerability has a high severity score and defenders should prioritize verifying the vulnerability and applying patches or mitigations to prevent potential attacks. The affected product is Axel Download Accelerator versions 2.17.14 and earlier.

Defensive priority

Defenders should prioritize verifying the vulnerability and applying patches or mitigations to prevent potential attacks.

Recommended defensive actions

• Verify the version of Axel Download Accelerator being used and check if it is vulnerable.
• Apply patches or updates to fix the vulnerability.
• Implement mitigations such as restricting access to the download accelerator or monitoring for suspicious activity.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The vulnerability is caused by the URL percent-decoding feature in Axel Download Accelerator, which allows an attacker to embed directory traversal sequences in the URL path. This can cause the download accelerator to write downloaded content to arbitrary filesystem paths relative to the current working directory. The CVE record was published on 2026-10-28T12:17:40.370Z and has not been modified since then. The official CVE Program record and NIST NVD detail page provide additional information on the vulnerability.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.