erl_tar:extract/2 loops forever on a GNU sparse member with a trailing hole
## Summary 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, correspondi
- Products
- hex_core
- Affected versions
- 0.14.0, 0.14.1, 0.15.0, 0.16.0, 0.16.1, 0.17.0, 0.18.0, 0.19.0, 0.20.0
- Fixed versions
- 0.20.1
- CVEs
- CVE-2026-96596
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 17:45 UTC · Revision 1
Source evidence
erl_tar:extract/2 loops forever on a GNU sparse member with a trailing hole
core-osv · Original sourcePublished 14 Oct 2026, 16:56 UTC
## Summary 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, correspondi
osv:EEF-CVE-2026-96596
hex_core
Fixed versions: 0.20.1
Complete source record
{
"id": "2d3b65752343ba1e72904651ee6871b6381165b5531e102a8f2ed7a05cd37833",
"url": "https://osv.dev/vulnerability/EEF-CVE-2026-96596",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "erl_tar:extract/2 loops forever on a GNU sparse member with a trailing hole",
"summary": "## Summary 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, correspondi",
"evidence": "osv:EEF-CVE-2026-96596",
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"EEF-CVE-2026-96596",
"GHSA-phm5-m6cj-5382"
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"metrics": [
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],
"modified": "2026-10-22T07:15:05.107023797Z",
"provider": "osv",
"references": [
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"https://cna.erlef.org/cves/CVE-2026-96596.html",
"https://www.erlang.org/doc/system/versions.html#order-of-versions",
"https://github.com/erlang/rebar3/commit/23dbdb5d1f87f56902aef296c88a20049cd0c6e4",
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"https://github.com/hexpm/hex_core/commit/a2ece683e6e88a3ec95ad20b09aca426e08b372e",
"https://github.com/erlang/otp/commit/fbf2c7194f6fce4b7b66dc0bcaa4f6b4b85e088f",
"https://github.com/erlang/otp/commit/3086307f311b78b38644a7787a3aca6a3f95a9d5",
"https://github.com/hexpm/hex/commit/5543a1919c709d8eb2b317f62aad76ca1eed375c",
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"https://github.com/hexpm/hex/commit/7847c23d09ab52113614c3718e1e7d368743da5d",
"https://hex.pm/packages/hex_core"
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"cpe:2.3:a:hexpm:hex_core:*:*:*:*:*:*:*:*",
"cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*",
"cpe:2.3:a:hexpm:hex:*:*:*:*:*:*:*:*"
],
"cwe_ids": [
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"capec_ids": [
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]
}
},
"related_cves": [
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"evidence": "/aliases"
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"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 404584,
"published_at": "2026-10-14T16:56:18.53+00:00"
}