GHSA-JMVV-89Q4-P2WR
Vulnerability from github – Published: 2026-08-15 15:30 – Updated: 2026-08-23 15:33In the Linux kernel, the following vulnerability has been resolved:
binfmt_misc: use exe_file_deny_write_access() for the interpreter clone
For MISC_FMT_OPEN_FILE entries load_misc_binary() clones the registered interpreter file and denies write access to the clone via plain deny_write_access(). The clone is installed as bprm->interpreter and later released by the exec machinery through exe_file_allow_write_access() which skips the i_writecount increment for files with FMODE_FSNOTIFY_HSM set.
The deny and allow side can therefore come to different conclusions when pre-content watches are in play: if a pre-content watch is added to the interpreter after registration every subsequent exec through that entry takes a write denial on the clone that is never paired with a write allowance, driving the interpreter inode's i_writecount further down with each exec and leaving the interpreter unwritable even after the entry and all its users are gone.
Take the write denial via exe_file_deny_write_access() so both sides of the pairing base their decision on the same file mode, and propagate failure instead of silently ignoring it: an interpreter that is concurrently open for writing now fails the exec with ETXTBSY, exactly like an interpreter freshly opened via open_exec() would.
{
"affected": [],
"aliases": [
"CVE-2026-74486"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T13:17:53Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbinfmt_misc: use exe_file_deny_write_access() for the interpreter clone\n\nFor MISC_FMT_OPEN_FILE entries load_misc_binary() clones the\nregistered interpreter file and denies write access to the clone via\nplain deny_write_access(). The clone is installed as\nbprm-\u003einterpreter and later released by the exec machinery through\nexe_file_allow_write_access() which skips the i_writecount increment\nfor files with FMODE_FSNOTIFY_HSM set.\n\nThe deny and allow side can therefore come to different conclusions\nwhen pre-content watches are in play: if a pre-content watch is added\nto the interpreter after registration every subsequent exec through\nthat entry takes a write denial on the clone that is never paired\nwith a write allowance, driving the interpreter inode\u0027s i_writecount\nfurther down with each exec and leaving the interpreter unwritable\neven after the entry and all its users are gone.\n\nTake the write denial via exe_file_deny_write_access() so both sides\nof the pairing base their decision on the same file mode, and\npropagate failure instead of silently ignoring it: an interpreter\nthat is concurrently open for writing now fails the exec with\nETXTBSY, exactly like an interpreter freshly opened via open_exec()\nwould.",
"id": "GHSA-jmvv-89q4-p2wr",
"modified": "2026-08-23T15:33:02Z",
"published": "2026-08-15T15:30:34Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74486"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/255a758697da87a205e072e0cfc35897b8f743b1"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2bd860b7e752a51185960143cab9fec7bf32c84e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2fdf8b07bee5ef99ec77773a6be05fbb8ee5cdb9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c65eb018c12179b5e2c7afe1f0956298576fecec"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/eea4b7c7711b1e425272d23352af157f45f4c3e3"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f0edbaf487e4653a680a7abb91c1df94cb7886aa"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f1e7ea3c8e070f19771cdaef55bbeda1359ad490"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fa5990ca8fd917003e526036bcc50413edb9722c"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Confirmed: The vulnerability has been validated from an analyst's perspective.
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- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.