Sudo: Privilege Dropping / Lowering Errors
CVE-2026-35535 is a high-severity privilege dropping / lowering errors vulnerability in Sudo from Sudo Project, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version 3e474c2f201484be83d994ae10a4e20e8c81bb69 as the first without the flaw, so updating Sudo to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.18% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Sudo to 3e474c2f201484be83d994ae10a4e20e8c81bb69 or a later version.
- Update RUGGEDCOM RST2428P to V4.0 or a later version.
- Update Sinec OS to 4.0 or a later version.
Affected products and versions
Version data comes from the organisation that assigned the CVE; 3 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.4 | High | CNA (mitre.org) |
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.4 | High | CNA |
Official description
In Sudo through 1.9.17p2 before 3e474c2, a failure of a setuid, setgid, or setgroups call, during a privilege drop before running the mailer, is not a fatal error and can lead to privilege escalation.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Privilege Dropping / Lowering Errors
The product does not drop privileges before passing control of a resource to an actor that does not have those privileges.
How developers prevent this class of flaw
- Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
More Privilege Dropping / Lowering Errors vulnerabilities (CWE-271)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Third-party and government advisories
- qualys.com/2026/03/10/crack-armor.txtThird Party Advisory
- cert-portal.siemens.com/productcert/html/ssa-253495.htmlThird Party Advisory
Other references
- bugs.launchpad.net/ubuntu/+source/sudo/+bug/2143042Issue Tracking
- lists.debian.org/debian-lts-announce/2026/06/msg00003.html
- access.redhat.com/errata/RHSA-2026:10758
- access.redhat.com/errata/RHSA-2026:11521
- access.redhat.com/errata/RHSA-2026:12310
- access.redhat.com/errata/RHSA-2026:13731
- access.redhat.com/errata/RHSA-2026:13888
- access.redhat.com/errata/RHSA-2026:13889
- access.redhat.com/errata/RHSA-2026:13891
- access.redhat.com/errata/RHSA-2026:13892
- access.redhat.com/errata/RHSA-2026:13895
- access.redhat.com/errata/RHSA-2026:13896
- access.redhat.com/errata/RHSA-2026:14228
- access.redhat.com/errata/RHSA-2026:14437
- access.redhat.com/errata/RHSA-2026:19067
Other vulnerabilities in Sudo
- 7.8 High severity
- 7.8 High severity
- 8.8 High severity
- 7.8 High severity
- 7.1 High severity
- 7.8 High severity
Sudo Heap-Based Buffer Overflow Exploited
Recent Privilege Dropping / Lowering Errors vulnerabilities
- 7.9 High severity
- 8.0 High severity
- 8.8 High severity
- 7.8 High severity
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