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GHSA-H639-9H3V-CF49

Vulnerability from github – Published: 2026-07-22 18:32 – Updated: 2026-07-22 18:32

Details

A flaw was found in systemd-tmpfiles. When processing a tmpfiles.d configuration entry that writes to a file, systemd-tmpfiles can follow a symbolic link placed by an unprivileged local user, and an existing safety check does not detect this specific case because it always treats transitions away from the root user as safe. On systems where a tmpfiles.d configuration targets a path an unprivileged user can influence, this could allow that user to redirect a privileged systemd-tmpfiles write to a file of their choosing, though the content written remains determined by the existing configuration rather than by the unprivileged user. The highest threat from this vulnerability is to integrity.

Severity

6.3 (Medium)


                  
                    CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-16552"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-59"
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    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-22T16:17:16Z",
    "severity": "MODERATE"
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  "id": "GHSA-h639-9h3v-cf49",
  "modified": "2026-07-22T18:32:35Z",
  "published": "2026-07-22T18:32:35Z",
  "references": [
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      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-16552"
    },
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    },
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    },
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      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-16552 (GCVE-0-2026-16552)

Vulnerability from cvelistv5 – Published: 2026-07-22 15:55 – Updated: 2026-07-22 16:08

Title

Systemd: systemd-tmpfiles symlink-redirected arbitrary file overwrite via a chase_safe root-to-unprivileged ownership transition bypass

Summary

Severity

6.3 (Medium)


                        
                          CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-59 - Improper Link Resolution Before File Access ('Link Following')

Assigner

redhat

References

4 references

URL	Tags
https://access.redhat.com/security/cve/CVE-2026-16552	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2506073	issue-trackingx_refsource_REDHAT
https://github.com/systemd/systemd/blob/b9ef5951f…
https://github.com/systemd/systemd/blob/b9ef5951f…

Impacted products

6 products

Vendor	Product	Version
Red Hat	Red Hat Enterprise Linux 10	cpe:/o:redhat:enterprise_linux:10
Red Hat	Red Hat Enterprise Linux 7	cpe:/o:redhat:enterprise_linux:7
Red Hat	Red Hat Enterprise Linux 8	cpe:/o:redhat:enterprise_linux:8
Red Hat	Red Hat Enterprise Linux 9	cpe:/o:redhat:enterprise_linux:9
Red Hat	Red Hat Hardened Images	cpe:/a:redhat:hummingbird:1
Red Hat	Red Hat OpenShift Container Platform 4	cpe:/a:redhat:openshift:4

Date Public

2026-07-22 00:00

Credits

Red Hat would like to thank İbrahim Sağlam (Eresus Security) for reporting this issue.

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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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

GHSA-H639-9H3V-CF49

CVE-2026-16552 (GCVE-0-2026-16552)

Tags

Sightings

Nomenclature