CVE-2026-47076 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-47076MEDIUM

benoitc hackney — SSRF allowlist bypass via percent-encoded host in hackney

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   L   L   P   N   N   H   N   N    6.9   .0023   14.0     —

AFFECTED
  Product  Versions                                    Fixed
  hackney  0.13.0 –                                    —
  hackney  4d725507588942fd00efca15b86da3273656510a –  —

TIMELINE
  May 18  Reserved by EEF
  May 25  EXPLOIT PUBLISHED — CVE-2026-47076 (benoitc hackney). Public exploit reference added.
  May 25  Published (CNA: EEF)

CWE-436, CWE-918 · CNA: EEF · CVSS v4.0 · 4 references · NVD status: Analyzed

Description

Interpretation Conflict vulnerability in benoitc hackney allows Server Side Request Forgery. hackney_url:normalize/2 URL-decodes the host component after the URL has been parsed into a #hackney_url{} record. OTP's uri_string:parse/1 and inet:parse_address/1 do not decode percent-escapes in the host, so a URL such as http://%31%32%37%2E%30%2E%30%2E%31/ is seen by a caller's allowlist validator with host %31%32%37%2E%30%2E%30%2E%31 (not an IP address), which passes the allowlist check. hackney's normalizer then decodes the host to 127.0.0.1 and opens a TCP connection to loopback. Because hackney:request/5 always calls hackney_url:normalize/2 with no opt-out, every request that takes a binary or list URL is affected. The same technique reaches cloud instance metadata services (169.254.169.254), RFC1918 networks, and any admin interface listening on localhost. This issue affects hackney: from 0.13.0 before 4.0.1.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
May 18, 2026	Reserved	Reserved by EEF
May 25, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-47076 (benoitc hackney). Public exploit reference added.
May 25, 2026	Published	Published (CNA: EEF)

Affected

Affected products and packages — 2 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
benoitc	hackney	—	0.13.0	—
benoitc	hackney	—	4d725507588942fd00efca15b86da3273656510a	—

Weaknesses

CWE-436 · CWE-918

References (4)

https://cna.erlef.org/cves/CVE-2026-47076.html [Patch, Third Party Advisory]
https://github.com/benoitc/hackney/commit/452620a92ec1da2e6b4862a049a2a4f04b42068f [Patch]
https://github.com/benoitc/hackney/security/advisories/GHSA-pj7v-xfvx-wmjq [Exploit, Patch, Vendor Advisory]
https://osv.dev/vulnerability/EEF-CVE-2026-47076 [Patch, Third Party Advisory]

Authoritative record: CVE-2026-47076 at cve.org

Vendors: benoitc

Weaknesses: CWE-436 · CWE-918

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-47076 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.