CVE-2026-39803

Allocation of Resources Without Limits or Throttling vulnerability in mtrudel bandit allows unauthenticated remote denial of service via memory exhaustion. The chunked clause of 'Elixir.Bandit.HTTP1.Socket':read_data/2 in lib/bandit/http1/socket.ex ignores the caller-supplied :length option when reading HTTP/1 chunked request bodies. Instead of capping the accumulated body at the configured limit (e.g. Plug.Parsers' default 8 MB), do_read_chunked_data!/5 buffers every received chunk into an iolist unconditionally and materializes the entire body as a single binary. The function always returns {:ok, body, ...}, so callers cannot interpose a 413 response. Because Plug.Parsers runs before routing and authentication in the standard Phoenix endpoint, an unauthenticated attacker needs no valid route or credentials. Sending a single Transfer-Encoding: chunked POST request with an arbitrarily large body to any path causes the BEAM process to exhaust available memory and be terminated by the OS OOM killer. The content-length path in the same function correctly enforces the limit and is not affected. This issue affects bandit: from 1.4.0 before 1.11.1.

• CWE-770

• https://cna.erlef.org/cves/CVE-2026-39803.htmlThird Party Advisory
• https://github.com/mtrudel/bandit/commit/ae3520dfdbfab115c638f8c7f6f6b805db34e1abPatch
• https://github.com/mtrudel/bandit/security/advisories/GHSA-9q9q-324x-93r2Exploit, Vendor Advisory
• https://osv.dev/vulnerability/EEF-CVE-2026-39803Third Party Advisory
• https://github.com/mtrudel/bandit/security/advisories/GHSA-9q9q-324x-93r2Exploit, Vendor Advisory

Published

May 13, 2026

Last Modified

Jun 17, 2026

Status

Analyzed

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-3975A security flaw has been discovered in Tenda W3 1.0.0.3(2204…8.8
• CVE-2026-3976A weakness has been identified in Tenda W3 1.0.0.3(2204). Im…8.8
• CVE-2026-3977A security vulnerability has been detected in projectsend up…6.3
• CVE-2026-3978A vulnerability was detected in D-Link DIR-513 1.10. The imp…8.8
• CVE-2026-3979A flaw has been found in quickjs-ng quickjs up to 0.12.1. Th…5.3
• CVE-2026-3980A vulnerability has been found in itsourcecode Online Doctor…9.8
• CVE-2026-39804Allocation of Resources Without Limits or Throttling vulnera…8.2
• CVE-2026-39805Inconsistent Interpretation of HTTP Requests vulnerability i…6.3
• CVE-2026-39806Loop with Unreachable Exit Condition ('Infinite Loop') vulne…7.5
• CVE-2026-39807Reliance on Untrusted Inputs in a Security Decision vulnerab…6.3
• CVE-2026-39808A improper neutralization of special elements used in an os …9.8
• CVE-2026-39809A improper neutralization of special elements used in an sql…6.7