CVE-2026-115700 benoitc CVE debrief

Who should care

Defenders and developers using hackney versions between 4.0.1 and 4.9.0 should assess exposure and apply patches. They should also review allowlists built on uri_string:parse/1 and inet:parse_address/1, and monitor for unusual activity. Security teams and vulnerability management teams should prioritize verifying exposure and applying patches for hackney versions between 4.0.1 and 4.9.0.

Why it matters

CVE-2026-115700 allows Server Side Request Forgery in hackney_url, affecting hackney versions from 4.0.1 before 4.9.0. Defenders should verify exposure, apply patches, and monitor for unusual activity.

• Verify allowlists and IP address parsing
• Monitor for unusual activity and potential SSRF
• Apply patches for hackney versions between 4.0.1 and 4.9.0

Technical summary

The hackney_url in benoitc hackney is vulnerable to Server Side Request Forgery due to an interpretation conflict. A percent-encoded bracketed IPv6 literal or an IP literal with a trailing dot can bypass the IP-literal gate and connect to the denoted address. This issue affects hackney versions from 4.0.1 before 4.9.0. The vulnerability has a CVSS score of 6.9 and is classified as MEDIUM severity. Defenders should prioritize verifying exposure and applying patches for hackney versions between 4.0.1 and 4.9.0. The issue arises from the way hackney_url handles IP literals and percent-encoded bracketed IPv6 literals.

Defensive priority

Defenders should prioritize verifying exposure and applying patches for hackney versions between 4.0.1 and 4.9.0.

Recommended defensive actions

• Verify hackney version and apply patches if necessary
• Review allowlists built on uri_string:parse/1 and inet:parse_address/1
• Monitor for unusual activity
• 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
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, but additional information on exploitation and impact is limited. There is no evidence of public exploitation. The CVE was published on 2026-10-26T14:16:32.080Z and has not been modified since then. The NVD entry provides a detailed description of the vulnerability and its impact.

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.