CVE-2026-56814
- Source
- https://cve.org/CVERecord?id=CVE-2026-56814
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56814.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-56814
- Aliases
-
- EEF-CVE-2026-56814
- GHSA-95qv-c9g9-rm63
- Published
- 2026-07-10T11:14:35Z
- Modified
- 2026-10-08T02:51:09Z
- Severity
-
- 6.9 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N CVSS Calculator
- Summary
- Plug: multipart :length limit is not charged for part headers, enabling unbounded temp-file creation (denial of service)
- Details
-
Plug.Parsers.MULTIPART, the multipart request-body parser used to handle file uploads and multipart forms, does not enforce its :length budget against all consumed resources, allowing an unauthenticated remote attacker to cause denial of service. The parser charges the :length limit only for part body bytes; part header bytes are never counted, and a part with an empty body costs zero.
Because every part whose Content-Disposition carries a non-empty filename creates a fresh temporary file (via Plug.Upload) and retains a Plug.Upload struct for the duration of the request, an attacker can send a single request composed of many empty-body file parts. Such a request stays well under the configured :length limit (8,000,000 bytes by default) while creating one temporary file per part, leading to inode and disk exhaustion and unbounded memory growth. Any application using Plug.Parsers with the :multipart parser is affected, and no authentication is required, only reachability of a multipart endpoint over HTTP.
This vulnerability is associated with program files lib/plug/parsers/multipart.ex and program routines Plug.Parsers.MULTIPART.parse_multipart/2, Plug.Parsers.MULTIPART.parse_multipart_headers/5, Plug.Parsers.MULTIPART.parse_multipart_body/4, and Plug.Parsers.MULTIPART.parse_multipart_file/4.
This issue affects plug: from 1.4.0-rc.0 before 1.16.6, from 1.17.0 before 1.17.4, from 1.18.0 before 1.18.5, from 1.19.1 before 1.19.5, and from 1.20.0 before 1.20.3.
- Database specific
{ "cna_assigner": "EEF", "cwe_ids": [ "CWE-770" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56814.json", "unresolved_ranges": [ { "extracted_events": [ { "introduced": "1.4.0-rc.0" }, { "fixed": "1.16.6" }, { "introduced": "1.17.0" }, { "fixed": "1.17.4" }, { "introduced": "1.18.0" }, { "fixed": "1.18.5" }, { "introduced": "1.19.1" }, { "fixed": "1.19.5" }, { "introduced": "1.20.0" }, { "fixed": "1.20.3" } ], "source": "AFFECTED_FIELD" } ] }- References
-
- https://cna.erlef.org/cves/CVE-2026-56814.html
- https://github.com
- https://osv.dev/vulnerability/EEF-CVE-2026-56814
- https://repo.hex.pm
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56814.json
- https://github.com/elixir-plug/plug/security/advisories/GHSA-95qv-c9g9-rm63
- https://nvd.nist.gov/vuln/detail/CVE-2026-56814
- https://github.com/elixir-plug/plug/commit/0ee8afcc61466dc5f7a8f048d0632c899165b81f
- https://github.com/elixir-plug/plug/commit/56edca2ce35fe5589cd581644d8a4493fa5f484e
- https://github.com/elixir-plug/plug/commit/981597d3a4271ede64373c7a731702a42c500dd6
- https://github.com/elixir-plug/plug/commit/c52b2f32c90bccd718202bafccb5f95594e30183
- https://github.com/elixir-plug/plug/commit/cae36053350e5215a4e0ca33cd130af9c5fc6364
- https://github.com/elixir-plug/plug/commit/df97d3f17f808a9916a7700a701fb85314559d56
- https://github.com/elixir-plug/plug/commit/f7effaed811c00b5f5bf817936bfd9c5df27b7dc
- https://github.com/elixir-plug/plug