CVE-2026-89987: Software Security Vulnerability Vulnerability

UNKNOWN
Advisory Identifier: GHSA-44gm-xvpq-cmx6
Share
Published
Advisory Summary

CVE-2026-89987 is a security vulnerability vulnerability (General Security Weakness) affecting Software libraries in the Maven ecosystem. Remediation is available in the latest vendor maintenance releases.

CVE-2026-89987 at a Glance

CVE Identifier CVE-2026-89987
GHSA Identifier GHSA-44gm-xvpq-cmx6
Severity N/A
CVSS v3.1 Base Score N/A
CWE Classification General Security Weakness
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-89987

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-89987, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under General Security Weakness. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

In the Linux kernel, the following vulnerability has been resolved: mm/huge_memory: transfer the pmd dirty bit to the folio on zap zap_huge_pmd_folio() propagates the pmd young bit to the folio for the file case, but not the dirty bit. The pte path does propagate it, in zap_present_folio_ptes() and so does the pmd split path, in __split_huge_pmd_locked(). For most file mappings the omission is harmless, because writing to a shared file mapping goes through page_mkwrite(), which dirties the folio. tmpfs is different: it has no page_mkwrite(), and vma_wants_writenotify() is false for it, so a *read* fault on a MAP_SHARED tmpfs mapping installs a writable pmd via do_read_fault(). do_read_fault() does not call fault_dirty_shared_page(), so subsequent stores through that mapping set only the hardware dirty bit in the pmd and never call folio_mark_dirty(). A shmem folio allocated by a fault is marked uptodate but not dirty (see the clear: block in shmem_get_folio_gfp()), so PG_dirty is never set at all. Unmapping such a folio - munmap(), or exit_mmap() when the process dies - then loses the only record that it was written, because zap_huge_pmd() drops the pmd without transferring the dirty bit. Reclaim afterwards sees a clean shmem folio: the whole swap-out block in shrink_folio_list() is inside "if (folio_test_dirty(folio))", so pageout() is skipped and the folio falls into __remove_mapping(). There, folio_is_file_lru() is false for a swapbacked folio, so no shadow entry is created and __filemap_remove_folio(folio, NULL) simply empties the i_pages slot. The data is freed without ever being written to swap, and the next fault on that index returns a freshly zeroed folio. This is silent data loss for any process that keeps state in a MAP_SHARED tmpfs segment across an unmap - for example a cache handed from one process generation to the next through /dev/shm. It requires the folio to be PMD-mapped, so it only shows up once shmem THP is enabled (which is what we did in Meta fleet and started noticing crashes); with THP off the pte path transfers the dirty bit correctly. It also only becomes visible when swap is enabled, because with no swap device shmem folios (which are on the anon LRU) are not scanned by reclaim at all, so the clean folio is never dropped. Reproduced on x86_64 with a tmpfs mounted huge=within_size: read-fault a 2MB-backed region, write a known pattern through the resulting mapping, munmap, force reclaim of the cgroup, then re-map and read back. Without this patch the region reads back as zeros and vmstat shows zswpout 0 - the data was discarded rather than swapped. With this patch the region reads back correctly and the pages are swapped out as expected. With huge=never, or when the first touch is a write, the test passes either way.

References

NVD — CVE-2026-89987 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89987
git.kernel.org/stable/c/9435cddf13... WEB
https://git.kernel.org/stable/c/9435cddf1378d149d826bd7bd1448a44bf96868d
git.kernel.org/stable/c/effe3cc6d4... WEB
https://git.kernel.org/stable/c/effe3cc6d4fdd407457eb30f7b0ef094393f0d64
git.kernel.org/stable/c/fe6cf98493... WEB
https://git.kernel.org/stable/c/fe6cf984939d8e12cb33a99673c8d026c5135e68

Frequently Asked Questions

What is CVE-2026-89987?
CVE-2026-89987 is a security vulnerability in Software classified as a security vulnerability vulnerability under General Security Weakness.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-89987?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-89987?
CVE-2026-89987 is classified under General Security Weakness.
How can I check Maven dependencies for CVE-2026-89987?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-44gm-xvpq-cmx6",
  "modified" : "2026-09-16T12:30:44Z",
  "published" : "2026-09-16T12:30:44Z",
  "aliases" : [ "CVE-2026-89987" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/huge_memory: transfer the pmd dirty bit to the folio on zap\n\nzap_huge_pmd_folio() propagates the pmd young bit to the folio for the\nfile case, but not the dirty bit.  The pte path does propagate it, in\nzap_present_folio_ptes() and so does the pmd split path, in\n__split_huge_pmd_locked().\n\nFor most file mappings the omission is harmless, because writing to a\nshared file mapping goes through page_mkwrite(), which dirties the folio. \ntmpfs is different: it has no page_mkwrite(), and vma_wants_writenotify()\nis false for it, so a *read* fault on a MAP_SHARED tmpfs mapping installs\na writable pmd via do_read_fault().  do_read_fault() does not call\nfault_dirty_shared_page(), so subsequent stores through that mapping set\nonly the hardware dirty bit in the pmd and never call folio_mark_dirty(). \nA shmem folio allocated by a fault is marked uptodate but not dirty (see\nthe clear: block in shmem_get_folio_gfp()), so PG_dirty is never set at\nall.\n\nUnmapping such a folio - munmap(), or exit_mmap() when the process dies -\nthen loses the only record that it was written, because zap_huge_pmd()\ndrops the pmd without transferring the dirty bit.  Reclaim afterwards sees\na clean shmem folio: the whole swap-out block in shrink_folio_list() is\ninside \"if (folio_test_dirty(folio))\", so pageout() is skipped and the\nfolio falls into __remove_mapping().  There, folio_is_file_lru() is false\nfor a swapbacked folio, so no shadow entry is created and\n__filemap_remove_folio(folio, NULL) simply empties the i_pages slot.  The\ndata is freed without ever being written to swap, and the next fault on\nthat index returns a freshly zeroed folio.\n\nThis is silent data loss for any process that keeps state in a MAP_SHARED\ntmpfs segment across an unmap - for example a cache handed from one\nprocess generation to the next through /dev/shm.  It requires the folio to\nbe PMD-mapped, so it only shows up once shmem THP is enabled (which is\nwhat we did in Meta fleet and started noticing crashes); with THP off the\npte path transfers the dirty bit correctly.  It also only becomes visible\nwhen swap is enabled, because with no swap device shmem folios (which are\non the anon LRU) are not scanned by reclaim at all, so the clean folio is\nnever dropped.\n\nReproduced on x86_64 with a tmpfs mounted huge=within_size: read-fault a\n2MB-backed region, write a known pattern through the resulting mapping,\nmunmap, force reclaim of the cgroup, then re-map and read back.  Without\nthis patch the region reads back as zeros and vmstat shows zswpout 0 - the\ndata was discarded rather than swapped.  With this patch the region reads\nback correctly and the pages are swapped out as expected.  With\nhuge=never, or when the first touch is a write, the test passes either\nway.",
  "severity" : [ ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-89987"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/9435cddf1378d149d826bd7bd1448a44bf96868d"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/effe3cc6d4fdd407457eb30f7b0ef094393f0d64"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/fe6cf984939d8e12cb33a99673c8d026c5135e68"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : null,
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-16T11:17:09Z"
  }
}