CVE-2026-77972
- Source
- https://cve.org/CVERecord?id=CVE-2026-77972
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-77972.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-77972
- Aliases
- Published
- 2026-09-15T15:37:49Z
- Modified
- 2026-09-23T03:30:27Z
- Severity
-
- 9.0 (Critical) CVSS_V4 - CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N CVSS Calculator
- Summary
- safeurl validated address is not bound to the request, allowing DNS rebinding
- Details
-
Time-of-check Time-of-use (TOCTOU) Race Condition in Slab safeurl allows an attacker who controls a hostname's DNS responses to reach internal network destinations that validation rejected.
Validation returns a verdict and not the address it approved, so the HTTP clients the library ships receive the original hostname and resolve it a second time when the request is made. An attacker who controls the authoritative DNS for a name can answer the first lookup with a permitted address and the second with a blocked one, and the request then reaches a destination validation never approved. The same window opens without an attacker whenever a name legitimately resolves to different addresses across lookups, such as short record lifetimes or rotation between several addresses.
This issue affects safeurl: from 0.1.0 onward.
- Database specific
{ "cna_assigner": "EEF", "cwe_ids": [ "CWE-367" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77972.json", "unresolved_ranges": [ { "extracted_events": [ { "introduced": "0.1.0" }, { "fixed": "*" }, { "introduced": "feabbd0a13f83028ab24b71710526e9da9841f70" }, { "fixed": "*" } ], "source": "AFFECTED_FIELD" } ] }- References
-
- https://github.com
- https://osv.dev/vulnerability/EEF-CVE-2026-77972
- https://repo.hex.pm
- https://cna.erlef.org/cves/CVE-2026-77972.html
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77972.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-77972
- https://github.com/slab/safeurl-elixir/commit/feabbd0a13f83028ab24b71710526e9da9841f70
- https://github.com/slab/safeurl-elixir