CVE-2026-96596

MEDIUMCVSS 5.9/10EPSS 0.19%

Last modified

CVE-2026-96596 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. 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. EPSS estimates a 0.19% chance of exploitation in the next 30 days.

Description

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, and stdlib from 8.0 before 8.1.1, and hex from 2.4.2 before 2.5.3; hex_core: from 0.14.0 before 0.20.1.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
ErlangOTP>= 29.0, < 29.1.2
ErlangOTP>= 8.0, < 8.1.1
ErlangOTP>= fbf2c7194f6fce4b7b66dc0bcaa4f6b4b85e088f, < 3086307f311b78b38644a7787a3aca6a3f95a9d5
erlangrebar3>= 3.27.1, < *
erlangrebar3>= 23dbdb5d1f87f56902aef296c88a20049cd0c6e4, < *
hexpmhex_core>= 0.14.0, < 0.20.1
hexpmhex_core>= 13bb9fbba418a406af614790b8d5cd458259ee70, < a2ece683e6e88a3ec95ad20b09aca426e08b372e
hexpmhex>= 2.4.2, < 2.5.3
hexpmhex>= 5543a1919c709d8eb2b317f62aad76ca1eed375c, < *

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-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 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, and stdlib from 8.0 before 8.1.1, and hex from 2.4.2 before 2.5.3; hex_core: from 0.14.0 before 0.20.1.
How severe is CVE-2026-96596?
CVE-2026-96596 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.
How do I fix CVE-2026-96596?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST