Medium

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

Type: advisorySource: Official CVE List1 source record

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_file_loop/3 reads it in chunks of 65536 bytes by default. For a GNU sparse member whose sparse map ends before its real size, erl_tar:do_sparse_read/3 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 {max_size, N} option prevents this only when N is below the real size of the member. Extraction with the memory option is not affected. hex_core ships its own copy of erl_tar as hex_erl_tar, and Hex and rebar3 ship hex_core with prefixed module names (mix_hex_erl_tar and r3_hex_erl_tar). These copies contain the same code and do not call stdlib's erl_tar, 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 rebar3 from 3.27.1 before 3.28.0,

Announced 14 Oct 2026Source revision 1

Original source ↗

CVE-2026-96596

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-96596

rebar3

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

rebar3

Source reference: /containers/cna/affected/1/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

hex_core

Source reference: /containers/cna/affected/2/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

hex_core

Source reference: /containers/cna/affected/3/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

OTP

Source reference: /containers/cna/affected/4/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

OTP

Source reference: /containers/cna/affected/5/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

OTP

Source reference: /containers/cna/affected/6/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

hex

Source reference: /containers/cna/affected/7/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

hex

Source reference: /containers/cna/affected/8/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "cpes": [
      "cpe:2.3:a:erlang:rebar3:*:*:*:*:*:*:*:*"
    ],
    "repo": "https://github.com/erlang/rebar3",
    "vendor": "erlang",
    "modules": [
      "r3_hex_erl_tar",
      "r3_hex_tarball"
    ],
    "product": "rebar3",
    "versions": [
      {
        "status": "affected",
        "version": "3.27.1",
        "lessThan": "3.28.0",
        "versionType": "semver"
      }
    ],
    "packageURL": "pkg:otp/rebar3?repository_url=https:%2F%2Fgithub.com%2Ferlang%2Frebar3&vcs_url=git%2Bhttps:%2F%2Fgithub.com%2Ferlang%2Frebar3.git",
    "packageName": "rebar3",
    "programFiles": [
      "apps/rebar/src/vendored/r3_hex_erl_tar.erl",
      "apps/rebar/src/vendored/r3_hex_tarball.erl"
    ],
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "r3_hex_erl_tar:do_sparse_read/3"
      },
      {
        "name": "r3_hex_erl_tar:stream_to_file_loop/3"
      },
      {
        "name": "r3_hex_erl_tar:extract/1"
      },
      {
        "name": "r3_hex_erl_tar:extract/2"
      },
      {
        "name": "r3_hex_tarball:unpack/2"
      },
      {
        "name": "r3_hex_tarball:unpack/3"
      },
      {
        "name": "r3_hex_tarball:unpack_docs/2"
      },
      {
        "name": "r3_hex_tarball:unpack_docs/3"
      }
    ]
  },
  {
    "cpes": [
      "cpe:2.3:a:erlang:rebar3:*:*:*:*:*:*:*:*"
    ],
    "repo": "https://github.com/erlang/rebar3",
    "vendor": "erlang",
    "modules": [
      "r3_hex_erl_tar",
      "r3_hex_tarball"
    ],
    "product": "rebar3",
    "versions": [
      {
        "status": "affected",
        "version": "23dbdb5d1f87f56902aef296c88a20049cd0c6e4",
        "lessThan": "310e2ec8c7dd3df05d67af2b7fae23f30fc523c4",
        "versionType": "git"
      }
    ],
    "packageURL": "pkg:github/erlang/rebar3",
    "packageName": "erlang/rebar3",
    "programFiles": [
      "apps/rebar/src/vendored/r3_hex_erl_tar.erl",
      "apps/rebar/src/vendored/r3_hex_tarball.erl"
    ],
    "collectionURL": "https://github.com",
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "r3_hex_erl_tar:do_sparse_read/3"
      },
      {
        "name": "r3_hex_erl_tar:stream_to_file_loop/3"
      },
      {
        "name": "r3_hex_erl_tar:extract/1"
      },
      {
        "name": "r3_hex_erl_tar:extract/2"
      },
      {
        "name": "r3_hex_tarball:unpack/2"
      },
      {
        "name": "r3_hex_tarball:unpack/3"
      },
      {
        "name": "r3_hex_tarball:unpack_docs/2"
      },
      {
        "name": "r3_hex_tarball:unpack_docs/3"
      }
    ]
  },
  {
    "cpes": [
      "cpe:2.3:a:hexpm:hex_core:*:*:*:*:*:*:*:*"
    ],
    "repo": "https://github.com/hexpm/hex_core",
    "vendor": "hexpm",
    "modules": [
      "hex_erl_tar",
      "hex_tarball"
    ],
    "product": "hex_core",
    "versions": [
      {
        "status": "affected",
        "version": "0.14.0",
        "lessThan": "0.20.1",
        "versionType": "semver"
      }
    ],
    "packageURL": "pkg:hex/hex_core",
    "packageName": "hex_core",
    "programFiles": [
      "src/hex_erl_tar.erl",
      "src/hex_tarball.erl"
    ],
    "collectionURL": "https://repo.hex.pm",
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "hex_erl_tar:do_sparse_read/3"
      },
      {
        "name": "hex_erl_tar:stream_to_file_loop/3"
      },
      {
        "name": "hex_erl_tar:extract/1"
      },
      {
        "name": "hex_erl_tar:extract/2"
      },
      {
        "name": "hex_tarball:unpack/2"
      },
      {
        "name": "hex_tarball:unpack/3"
      },
      {
        "name": "hex_tarball:unpack_docs/2"
      },
      {
        "name": "hex_tarball:unpack_docs/3"
      }
    ]
  },
  {
    "cpes": [
      "cpe:2.3:a:hexpm:hex_core:*:*:*:*:*:*:*:*"
    ],
    "repo": "https://github.com/hexpm/hex_core",
    "vendor": "hexpm",
    "modules": [
      "hex_erl_tar",
      "hex_tarball"
    ],
    "product": "hex_core",
    "versions": [
      {
        "status": "affected",
        "version": "13bb9fbba418a406af614790b8d5cd458259ee70",
        "lessThan": "a2ece683e6e88a3ec95ad20b09aca426e08b372e",
        "versionType": "git"
      }
    ],
    "packageURL": "pkg:github/hexpm/hex_core",
    "packageName": "hexpm/hex_core",
    "programFiles": [
      "src/hex_erl_tar.erl",
      "src/hex_tarball.erl"
    ],
    "collectionURL": "https://github.com",
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "hex_erl_tar:do_sparse_read/3"
      },
      {
        "name": "hex_erl_tar:stream_to_file_loop/3"
      },
      {
        "name": "hex_erl_tar:extract/1"
      },
      {
        "name": "hex_erl_tar:extract/2"
      },
      {
        "name": "hex_tarball:unpack/2"
      },
      {
        "name": "hex_tarball:unpack/3"
      },
      {
        "name": "hex_tarball:unpack_docs/2"
      },
      {
        "name": "hex_tarball:unpack_docs/3"
      }
    ]
  },
  {
    "cpes": [
      "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"
    ],
    "vendor": "Erlang",
    "modules": [
      "erl_tar"
    ],
    "product": "OTP",
    "versions": [
      {
        "status": "affected",
        "version": "29.0",
        "lessThan": "29.1.2",
        "versionType": "otp"
      }
    ],
    "packageURL": "pkg:software-id/erlang.org/otp",
    "packageName": "otp",
    "programFiles": [
      "lib/stdlib/src/erl_tar.erl"
    ],
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "erl_tar:do_sparse_read/3"
      },
      {
        "name": "erl_tar:stream_to_file_loop/3"
      },
      {
        "name": "erl_tar:extract/1"
      },
      {
        "name": "erl_tar:extract/2"
      }
    ]
  },
  {
    "cpes": [
      "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"
    ],
    "repo": "https://github.com/erlang/otp",
    "vendor": "Erlang",
    "modules": [
      "erl_tar"
    ],
    "product": "OTP",
    "versions": [
      {
        "status": "affected",
        "version": "8.0",
        "lessThan": "8.1.1",
        "versionType": "otp"
      }
    ],
    "packageURL": "pkg:otp/stdlib?repository_url=https:%2F%2Fgithub.com%2Ferlang%2Fotp&vcs_url=git%2Bhttps:%2F%2Fgithub.com%2Ferlang%2Fotp.git",
    "packageName": "stdlib",
    "programFiles": [
      "src/erl_tar.erl"
    ],
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "erl_tar:do_sparse_read/3"
      },
      {
        "name": "erl_tar:stream_to_file_loop/3"
      },
      {
        "name": "erl_tar:extract/1"
      },
      {
        "name": "erl_tar:extract/2"
      }
    ]
  },
  {
    "cpes": [
      "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"
    ],
    "repo": "https://github.com/erlang/otp",
    "vendor": "Erlang",
    "modules": [
      "erl_tar"
    ],
    "product": "OTP",
    "versions": [
      {
        "status": "affected",
        "version": "fbf2c7194f6fce4b7b66dc0bcaa4f6b4b85e088f",
        "lessThan": "3086307f311b78b38644a7787a3aca6a3f95a9d5",
        "versionType": "git"
      }
    ],
    "packageURL": "pkg:github/erlang/otp",
    "packageName": "erlang/otp",
    "programFiles": [
      "lib/stdlib/src/erl_tar.erl"
    ],
    "collectionURL": "https://github.com",
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "erl_tar:do_sparse_read/3"
      },
      {
        "name": "erl_tar:stream_to_file_loop/3"
      },
      {
        "name": "erl_tar:extract/1"
      },
      {
        "name": "erl_tar:extract/2"
      }
    ]
  },
  {
    "cpes": [
      "cpe:2.3:a:hexpm:hex:*:*:*:*:*:*:*:*"
    ],
    "repo": "https://github.com/hexpm/hex",
    "vendor": "hexpm",
    "modules": [
      "mix_hex_erl_tar",
      "mix_hex_tarball"
    ],
    "product": "hex",
    "versions": [
      {
        "status": "affected",
        "version": "2.4.2",
        "lessThan": "2.5.3",
        "versionType": "semver"
      }
    ],
    "packageURL": "pkg:otp/hex?repository_url=https:%2F%2Fgithub.com%2Fhexpm%2Fhex&vcs_url=git%2Bhttps:%2F%2Fgithub.com%2Fhexpm%2Fhex.git",
    "packageName": "hex",
    "programFiles": [
      "src/mix_hex_erl_tar.erl",
      "src/mix_hex_tarball.erl"
    ],
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "mix_hex_erl_tar:do_sparse_read/3"
      },
      {
        "name": "mix_hex_erl_tar:stream_to_file_loop/3"
      },
      {
        "name": "mix_hex_erl_tar:extract/1"
      },
      {
        "name": "mix_hex_erl_tar:extract/2"
      },
      {
        "name": "mix_hex_tarball:unpack/2"
      },
      {
        "name": "mix_hex_tarball:unpack/3"
      },
      {
        "name": "mix_hex_tarball:unpack_docs/2"
      },
      {
        "name": "mix_hex_tarball:unpack_docs/3"
      }
    ]
  },
  {
    "cpes": [
      "cpe:2.3:a:hexpm:hex:*:*:*:*:*:*:*:*"
    ],
    "repo": "https://github.com/hexpm/hex",
    "vendor": "hexpm",
    "modules": [
      "mix_hex_erl_tar",
      "mix_hex_tarball"
    ],
    "product": "hex",
    "versions": [
      {
        "status": "affected",
        "changes": [
          {
            "at": "8e1067131a13949eff30623f31648a945ffd5418",
            "status": "unaffected"
          },
          {
            "at": "7847c23d09ab52113614c3718e1e7d368743da5d",
            "status": "unaffected"
          }
        ],
        "version": "5543a1919c709d8eb2b317f62aad76ca1eed375c",
        "lessThan": "*",
        "versionType": "git"
      }
    ],
    "packageURL": "pkg:github/hexpm/hex",
    "packageName": "hexpm/hex",
    "programFiles": [
      "src/mix_hex_erl_tar.erl",
      "src/mix_hex_tarball.erl"
    ],
    "collectionURL": "https://github.com",
    "defaultStatus": "unaffected",
    "programRoutines": [
      {
        "name": "mix_hex_erl_tar:do_sparse_read/3"
      },
      {
        "name": "mix_hex_erl_tar:stream_to_file_loop/3"
      },
      {
        "name": "mix_hex_erl_tar:extract/1"
      },
      {
        "name": "mix_hex_erl_tar:extract/2"
      },
      {
        "name": "mix_hex_tarball:unpack/2"
      },
      {
        "name": "mix_hex_tarball:unpack/3"
      },
      {
        "name": "mix_hex_tarball:unpack_docs/2"
      },
      {
        "name": "mix_hex_tarball:unpack_docs/3"
      }
    ]
  }
]

Related CVEs: CVE-2026-96596
Source reference: /cveMetadata/cveId

Publisher severity

medium

Source reference: /containers/cna/metrics

Event: #50145 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 14:01:59 GMT
Publisher date: Wed, 14 Oct 2026 16:56:18 GMT

Read the original announcement