Vulnerability-Lookup

GHSA-PCV7-392Q-P29W

Vulnerability from github – Published: 2026-10-28 12:31 – Updated: 2026-10-28 12:31

Details

In the Linux kernel, the following vulnerability has been resolved:

s390/ctcm: Prevent XID null dereference

The mpc_validate_xid() function sets grp->saved_xid2->xid2_flag2 to 0x40 to signal XID validation error. If peer XID is NULL or r/w channel pairing mismatch happens, grp->saved_xid2 is never initialized. An attempt to set the flag in such case leads to NULL dereference.

Fix this by using the always available priv->xid->xid2_flag2 instead of grp->saved_xid2->xid2_flag2 for validation errors.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-99126"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-28T11:17:32Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/ctcm: Prevent XID null dereference\n\nThe mpc_validate_xid() function sets grp-\u003esaved_xid2-\u003exid2_flag2 to 0x40\nto signal XID validation error. If peer XID is NULL or r/w channel\npairing mismatch happens, grp-\u003esaved_xid2 is never initialized. An\nattempt to set the flag in such case leads to NULL dereference.\n\nFix this by using the always available priv-\u003exid-\u003exid2_flag2 instead of\ngrp-\u003esaved_xid2-\u003exid2_flag2 for validation errors.",
  "id": "GHSA-pcv7-392q-p29w",
  "modified": "2026-10-28T12:31:04Z",
  "published": "2026-10-28T12:31:04Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99126"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/34fa3607b7604b3052b19cec8b0ad644818cdd2a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8a2f7a4ad1d81612fa65bfa4d392ba1bb2f5eeab"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b264d8422779d69febce914efc47a92a85cc382c"
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  "schema_version": "1.4.0",
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}

CVE-2026-99126 (GCVE-0-2026-99126)

Vulnerability from cvelistv5 – Published: 2026-10-28 10:34 – Updated: 2026-10-28 10:34

Title

s390/ctcm: Prevent XID null dereference

Summary

In the Linux kernel, the following vulnerability has been resolved: s390/ctcm: Prevent XID null dereference The mpc_validate_xid() function sets grp->saved_xid2->xid2_flag2 to 0x40 to signal XID validation error. If peer XID is NULL or r/w channel pairing mismatch happens, grp->saved_xid2 is never initialized. An attempt to set the flag in such case leads to NULL dereference. Fix this by using the always available priv->xid->xid2_flag2 instead of grp->saved_xid2->xid2_flag2 for validation errors.

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 7033 records in the last 180 days details

References

3 references

URL	Tags
https://git.kernel.org/stable/c/34fa3607b7604b305…
https://git.kernel.org/stable/c/8a2f7a4ad1d81612f…
https://git.kernel.org/stable/c/b264d8422779d69fe…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 293d984f0e3604c04dcdbf00117ddc1e5d4b1909 , < 34fa3607b7604b3052b19cec8b0ad644818cdd2a (git) Affected: 293d984f0e3604c04dcdbf00117ddc1e5d4b1909 , < 8a2f7a4ad1d81612fa65bfa4d392ba1bb2f5eeab (git) Affected: 293d984f0e3604c04dcdbf00117ddc1e5d4b1909 , < b264d8422779d69febce914efc47a92a85cc382c (git)
Linux	Linux	Affected: 2.6.26 Unaffected: 0 , < 2.6.26 (semver) Unaffected: 6.18.59 , ≤ 6.18.* (semver) Unaffected: 7.2.13 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
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          "programFiles": [
            "drivers/s390/net/ctcm_mpc.c"
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              "versionType": "git"
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          "vendor": "Linux",
          "versions": [
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              "status": "affected",
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      "cpeApplicability": [
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                  "vulnerable": true
                }
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              "negate": false,
              "operator": "OR"
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        {
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/ctcm: Prevent XID null dereference\n\nThe mpc_validate_xid() function sets grp-\u003esaved_xid2-\u003exid2_flag2 to 0x40\nto signal XID validation error. If peer XID is NULL or r/w channel\npairing mismatch happens, grp-\u003esaved_xid2 is never initialized. An\nattempt to set the flag in such case leads to NULL dereference.\n\nFix this by using the always available priv-\u003exid-\u003exid2_flag2 instead of\ngrp-\u003esaved_xid2-\u003exid2_flag2 for validation errors."
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
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.

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