[GHSA-8p33-q827-ghj5] dssrf: every IPv6 category bypasses is_url_safe

advisories/github-reviewed/2026/05/GHSA-8p33-q827-ghj5/GHSA-8p33-q827-ghj5.json

@@ -1,13 +1,13 @@
 {
   "schema_version": "1.4.0",
   "id": "GHSA-8p33-q827-ghj5",
-  "modified": "2026-05-06T18:13:32Z",
+  "modified": "2026-05-06T18:13:33Z",
   "published": "2026-05-06T18:13:32Z",
   "aliases": [
     "CVE-2026-44232"
   ],
   "summary": "dssrf: every IPv6 category bypasses is_url_safe",
-  "details": "A vulnerability in dssrf allows an attacker to bypass its SSRF protections by supplying one of the following IPv6 addresses, resulting in a successful SSRF. This contradicts dssrf documentation, which incorrectly claims that IPv6 is disabled entirely. See below:\n\n```rust\nInput\tCategory\nhttp://[::1]/\tIPv6 loopback\nhttp://[fc00::1]/\tIPv6 ULA\nhttp://[fe80::1]/\tIPv6 link-local\nhttp://[::ffff:127.0.0.1]/\tIPv4-mapped loopback\nhttp://[::ffff:169.254.169.254]/\tIPv4-mapped IMDS\nhttp://[::ffff:100.64.0.1]/\tIPv4-mapped CGNAT\nhttp://[64:ff9b::7f00:1]/\tNAT64 well-known prefix\nhttp://[64:ff9b:1::1]/\tNAT64 local-use (RFC 8215)\nhttp://[5f00::1]/\tSRv6 SID (RFC 9602)\nhttp://[3fff::1]/\tIPv6 documentation (RFC 9637)\nhttp://[fec0::1]/\tIPv6 site-local (deprecated, RFC 3879)\nhttp://[::127.0.0.1]/\tIPv4-compatible IPv6\n```\n\n### POC\n\n```bash\nmkdir dssrf-poc && cd dssrf-poc\nnpm init -y >/dev/null\nnpm install dssrf@^1.0.2\ncat > audit.js <<'EOF'\nconst dssrf = require('dssrf');\nconst cases = [\n  ['http://[::1]/',                         'IPv6 loopback'],\n  ['http://[fc00::1]/',                     'IPv6 ULA'],\n  ['http://[fe80::1]/',                     'IPv6 link-local'],\n  ['http://[::ffff:127.0.0.1]/',            'IPv4-mapped loopback'],\n  ['http://[::ffff:169.254.169.254]/',      'IPv4-mapped IMDS'],\n  ['http://[64:ff9b::7f00:1]/',             'NAT64 well-known + 127.0.0.1'],\n  ['http://[64:ff9b:1::1]/',                'NAT64 local-use (RFC 8215)'],\n  ['http://[5f00::1]/',                     'SRv6 SID (RFC 9602)'],\n  ['http://[fec0::1]/',                     'IPv6 site-local deprecated'],\n  ['http://127.0.0.1/',                     'IPv4 loopback (control)'],\n  ['http://10.0.0.1/',                      'IPv4 RFC1918 (control)'],\n  ['http://8.8.8.8/',                       'PUBLIC IPv4 (control)'],\n];\n(async () => {\n  for (const [url, label] of cases) {\n    const safe = await dssrf.is_url_safe(url);\n    console.log(`${safe ? '✓ALLOW' : '·block'}  ${url.padEnd(40)}  ${label}`);\n  }\n})();\nEOF\nnode audit.js\n```\n\n### Credit\ndssrf thanks <brmenna@gmail.com> for reporting this issue responsibly.\n\n### Update\nUsers should immediately update to dssrf 1.3.0.\n\n### Lessons Learned\nAs seen both in the past and today, many advisories and CVE bypasses leverage IPv6. IPv6 remains the weakest link, as it is rarely configured correctly and seldom tested. In this case, while IPv4 was properly blocked, the corresponding IPv6 blocking logic was completely broken and never actually worked.,",
+  "details": "A vulnerability in dssrf allows an attacker to bypass its SSRF protections by supplying one of the following IPv6 addresses, resulting in a successful SSRF. This contradicts dssrf documentation, which incorrectly claims that IPv6 is disabled entirely. See below:\n\n```rust\nInput\tCategory\nhttp://[::1]/\tIPv6 loopback\nhttp://[fc00::1]/\tIPv6 ULA\nhttp://[fe80::1]/\tIPv6 link-local\nhttp://[::ffff:127.0.0.1]/\tIPv4-mapped loopback\nhttp://[::ffff:169.254.169.254]/\tIPv4-mapped IMDS\nhttp://[::ffff:100.64.0.1]/\tIPv4-mapped CGNAT\nhttp://[64:ff9b::7f00:1]/\tNAT64 well-known prefix\nhttp://[64:ff9b:1::1]/\tNAT64 local-use (RFC 8215)\nhttp://[5f00::1]/\tSRv6 SID (RFC 9602)\nhttp://[3fff::1]/\tIPv6 documentation (RFC 9637)\nhttp://[fec0::1]/\tIPv6 site-local (deprecated, RFC 3879)\nhttp://[::127.0.0.1]/\tIPv4-compatible IPv6\n```\n\n### POC\n\n```bash\nmkdir dssrf-poc && cd dssrf-poc\nnpm init -y >/dev/null\nnpm install dssrf@^1.0.2\ncat > audit.js <<'EOF'\nconst dssrf = require('dssrf');\nconst cases = [\n  ['http://[::1]/',                         'IPv6 loopback'],\n  ['http://[fc00::1]/',                     'IPv6 ULA'],\n  ['http://[fe80::1]/',                     'IPv6 link-local'],\n  ['http://[::ffff:127.0.0.1]/',            'IPv4-mapped loopback'],\n  ['http://[::ffff:169.254.169.254]/',      'IPv4-mapped IMDS'],\n  ['http://[64:ff9b::7f00:1]/',             'NAT64 well-known + 127.0.0.1'],\n  ['http://[64:ff9b:1::1]/',                'NAT64 local-use (RFC 8215)'],\n  ['http://[5f00::1]/',                     'SRv6 SID (RFC 9602)'],\n  ['http://[fec0::1]/',                     'IPv6 site-local deprecated'],\n  ['http://127.0.0.1/',                     'IPv4 loopback (control)'],\n  ['http://10.0.0.1/',                      'IPv4 RFC1918 (control)'],\n  ['http://8.8.8.8/',                       'PUBLIC IPv4 (control)'],\n];\n(async () => {\n  for (const [url, label] of cases) {\n    const safe = await dssrf.is_url_safe(url);\n    console.log(`${safe ? '✓ALLOW' : '·block'}  ${url.padEnd(40)}  ${label}`);\n  }\n})();\nEOF\nnode audit.js\n```\n\n### Credit\ndssrf thanks <brmenna@gmail.com> for reporting this issue responsibly.\n\n### Update\nUsers should immediately update to dssrf 1.3.0.\n\n### Lessons Learned\nAs seen both in the past and today, many advisories and CVE bypasses leverage IPv6. IPv6 remains the weakest link, as it is rarely configured correctly and rarely properly tested. In this case, while IPv4 was properly blocked, the corresponding IPv6 blocking logic was completely broken and never actually worked.,",
   "severity": [
     {
       "type": "CVSS_V4",