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CVE-2026-96596

erl_tar:extract/2 loops forever on a GNU sparse member with a trailing hole

Published Oct 14, 2026 · corrected/updated Oct 15, 2026 · Erlang OTP · evidence confidence high

## Summary Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in Erlang OTP stdlib ( module), hexpm hex_core ( module), hexpm hex ( module) and erlang rebar3 ( module) allows an attacker who supplies a tar archive to cause a denial of service via a crafted GNU sparse member. When writes a member to disk, reads it in chunks of 65536 bytes by default. For a GNU sparse member whose sparse map ends before its real size, matches its trailing-hole clause before its zero-length clause. After the chunk is used up, the trailing-hole clause reads zero bytes, does not advance the position, and recurses forever. A 2048-byte archive keeps the extracting process and one scheduler busy until the process is killed. The option prevents this only when N is below the real size of the member. Extraction with the option is not affected. hex_core ships its own copy of as , and Hex and rebar3 ship hex_core with prefixed module names ( and ). These copies contain the same code and do not call stdlib's , so they are affected on any OTP version. OTP 28 is not affected, but an application running on OTP 28 is affected if it extracts archives through an affected version of hex_core, Hex or rebar3. This issue affects OTP from OTP 29.0 before OTP 29.1.2, corresponding to stdlib from 8.0 before 8.1.1, and rebar3 from 3.27.1 onward, and hex from 2.4.2 before 2.5.3; hex_core: from 0.14.0 before 0.20.1. ## Details **1. Chunked extraction.** writes each member to disk through . This function calls until the field of the reader is 0. The default chunk size is 65536 bytes. **2. Clause order in .** For a sparse member, calls . The clause for a trailing hole matches when is and . It comes before the clause that returns when is 0. **3. Unbounded recursion.** The member is a GNU sparse member (typeflag ) whose real size is larger than one chunk and whose sparse map ends before the real size. After the data fragments, the trailing-hole clause reads the rest of the chunk and recurses with .

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2026-96596 is a medium public vulnerability record for Erlang OTP. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether Erlang OTP is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: hex_core (0.14.0 → 0.20.1); Erlang OTP; erlang rebar3; hexpm hex. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 5.9, EPSS 0.2%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-835. Sources contributing to this record: circl, cve_org, epss, github. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.

  • Patch and remediation

    No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 14, 2026 · NIST NVD

    Detected

    Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in Erlang OTP stdlib (erl_tar module), hexpm hex_core (hex_erl_tar module), hexpm hex (mix_hex_erl_tar module) and erlang rebar3 (r3_hex_erl_tar module) allows an attacker who supplies a tar archive to cause a denial of service via a crafted GNU sparse member. When erl_tar:extract/1,2 writes a member to disk, erl_tar:stream_to_fi

  2. Oct 14, 2026 · GitHub Advisory Database

    Fix available

    hex_core fixed in 0.20.1

  3. Oct 14, 2026 · NIST NVD

    Updated

    Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in Erlang OTP stdlib (erl_tar module), hexpm hex_core (hex_erl_tar module), hexpm hex (mix_hex_erl_tar module) and erlang rebar3 (r3_hex_erl_tar module) allows an attacker who supplies a tar archive to cause a denial of service via a crafted GNU sparse member. When erl_tar:extract/1,2 writes a member to disk, erl_tar:stream_to_fi

  4. Oct 15, 2026 · GitHub Advisory Database

    Fix available

    hex_core fixed in 0.20.1

  5. Oct 15, 2026 · NIST NVD

    Updated

    Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in Erlang OTP stdlib (erl_tar module), hexpm hex_core (hex_erl_tar module), hexpm hex (mix_hex_erl_tar module) and erlang rebar3 (r3_hex_erl_tar module) allows an attacker who supplies a tar archive to cause a denial of service via a crafted GNU sparse member. When erl_tar:extract/1,2 writes a member to disk, erl_tar:stream_to_fi

Affected

  • Hex hex_core0.14.0 → 0.20.1
  • vendor Erlang OTPversion unspecified
  • vendor erlang rebar3version unspecified
  • vendor hexpm hexversion unspecified
  • vendor hexpm hex_coreversion unspecified

Sources

  • CIRCL Vulnerability LookupVulnerability recordCVE-2026-96596

    Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in Erlang OTP stdlib (erl_tar module), hexpm hex_core (hex_erl_tar module), hexpm hex (mix_hex_erl_tar module) and erlang rebar3 (r3_hex_erl_tar module) allows an attacker who supplies a tar archive to cause a d

    vulnerability.circl.lu
  • CVE.orgVulnerability recordCVE-2026-96596

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-96596

    30-day exploitation probability 0.2%

    first.org
  • GitHub Advisory DatabasePackage advisoryGHSA-phm5-m6cj-5382

    GitHub Advisory Database record mirrored by OSV.

    github.com
  • NIST NVDVulnerability recordCVE-2026-96596

    Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in Erlang OTP stdlib (erl_tar module), hexpm hex_core (hex_erl_tar module), hexpm hex (mix_hex_erl_tar module) and erlang rebar3 (r3_hex_erl_tar module) allows an attacker who supplies a tar archive to cause a d

    nvd.nist.gov
  • OSV.devPackage advisoryEEF-CVE-2026-96596

    erl_tar:extract/2 loops forever on a GNU sparse member with a trailing hole

    osv.dev

References