CVE-2026-96596
erl_tar:extract/2 loops forever on a GNU sparse member with a trailing hole
- Published
- Updated
- Reserved
- Assigned by
- EEF
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.
Timeline
ID reserved
By EEF
- 17 days later
· 17 days later
Published
- 8 days later
· 8 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| EEFCNA (assigner) | 4.0 | Medium5.9 | CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| NVDNVD · Deferred | 4.0 | Medium5.9 | CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.21% · top 88% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.9.
Weakness
Affected products
- affected 3.27.1 – < 3.28.0
- affected 23dbdb5d1f87f56902aef296c88a20049cd0c6e4 – < 310e2ec8c7dd3df05d67af2b7fae23f30fc523c4
- affected 0.14.0 – < 0.20.1
- affected 13bb9fbba418a406af614790b8d5cd458259ee70 – < a2ece683e6e88a3ec95ad20b09aca426e08b372e
- affected 29.0 – < 29.1.2
- affected 8.0 – < 8.1.1
- affected fbf2c7194f6fce4b7b66dc0bcaa4f6b4b85e088f – < 3086307f311b78b38644a7787a3aca6a3f95a9d5
- affected 2.4.2 – < 2.5.3
- affected 5543a1919c709d8eb2b317f62aad76ca1eed375c – < *
What to do
Workaround: Pass {chunks, N} together with {max_size, N}, with the same value N, to erl_tar:extract/2. Extraction then rejects any member larger than N, and reads each remaining member in one call, so the loop cannot occur. Alternatively, extract with the memory option and write the returned files to disk in the application.
References (13)
- GitHub Advisory (opens in a new tab)relatedvendor-advisory
- EEF CNA record for CVE-2026-96596 (opens in a new tab)related
- OSV record EEF-CVE-2026-96596 (opens in a new tab)related
- Erlang/OTP version ordering (opens in a new tab)x_version-scheme
- Introducing commit 23dbdb5 in erlang/rebar3 (opens in a new tab)related
- Fix commit 310e2ec in erlang/rebar3 (opens in a new tab)patch
- Introducing commit 13bb9fb in hexpm/hex_core (opens in a new tab)related
- Fix commit a2ece68 in hexpm/hex_core (opens in a new tab)patch
- Introducing commit fbf2c71 in erlang/otp (opens in a new tab)related
- Fix commit 3086307 in erlang/otp (opens in a new tab)patch
- Introducing commit 5543a19 in hexpm/hex (opens in a new tab)related
- Fix commit 8e10671 in hexpm/hex (opens in a new tab)patch
- Fix commit 7847c23 in hexpm/hex (opens in a new tab)patch
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-96596)Record last updated .