CVE-2026-12505

A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root privileges before looking up user information inside a user-controlled envir

Published Jun 18, 2026 · corrected/updated Oct 15, 2026 · evidence confidence high

A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root privileges before looking up user information inside a user-controlled environment. A local, low privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper into entering a custom environment (namespace) containing a malicious NSS module. This forces the system to load the attacker's controlled NSS Module and configuration, allowing them to execute arbitrary commands as the root user, elevating their privileges and fully compromising the system.

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2026-12505 is a high public vulnerability record for this product. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether this product is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: cifs-utils (2:7.0-2, 2:7.0-2.1, 2:7.1-1); cifs-utils (2:7.4-1, 2:7.8-1); cifs-utils (0 → 2:7.8-1). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 7.8, EPSS 0.2%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-250. Sources contributing to this record: cve_org, debian, epss, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

Exploitation evidence
Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Technology hubs

Debian

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

Jun 18, 2026 · NIST NVD
Detected
A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root privileges before looking up user information inside a user-controlled environment. A local, low privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper into entering a custom environment (namespace) containing a malicious NSS module. This force
Oct 14, 2026 · NIST NVD
Updated
A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root privileges before looking up user information inside a user-controlled environment. A local, low privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper into entering a custom environment (namespace) containing a malicious NSS module. This force
Oct 15, 2026 · OSV.dev
Fix available
cifs-utils fixed in 2:7.8-1
Oct 15, 2026 · OSV.dev
Fix available
cifs-utils fixed in 2:7.8-1
Oct 15, 2026 · OSV.dev
Updated
A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root privileges before looking up user information inside a user-controlled environment. A local, low privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper into entering a custom environment (namespace) containing a malicious NSS module. This force

Affected

Debian:12 cifs-utils2:7.0-2, 2:7.0-2.1, 2:7.1-1
Debian:13 cifs-utils2:7.4-1, 2:7.8-1
Debian:14 cifs-utils0 → 2:7.8-1

Sources

CVE.orgVulnerability recordCVE-2026-12505
Official CVE identifier
cve.org
Debian Security AdvisoriesVendor advisoryCVE-2026-12505
[SECURITY] [DSA 6567-1] cifs-utils security update
lists.debian.org
FIRST EPSSExploitation probabilityCVE-2026-12505
30-day exploitation probability 0.2%
first.org
NIST NVDVulnerability recordCVE-2026-12505
A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root privileges before looking up user information inside a user-controlled environment. A local, low privileged attacker can exploit this by using a crafted request_key payload to
nvd.nist.gov
OSV.devPackage advisoryDEBIAN-CVE-2026-12505
osv.dev