CVE-2026-35535: In Sudo through 1.9.17p2 before 3e474c2, a failure of a setuid, setgid, or setgroups call, during a privilege

Q: How do I fix CVE-2026-35535?

sudo: upgrade to 1.9.17; sinec os: upgrade to 4.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-35535 being exploited?

CVE-2026-35535 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-35535 affect?

CVE-2026-35535 affects sudo, sinec os. Severity is high (CVSS 7.4). 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.

Routine

HIGH 7.4UPGRADEUPGRADE

CVE-2026-35535 is a high-severity flaw (CVSS 7.4) affecting sudo, sinec os. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.4 (High)
Attack vector	Local
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.2% (top 93%)
CISA exploited list	No
Weakness	CWE-271, CWE-272
Published	2026-04-03
Last modified	2026-09-01

Publisher (CNA): MITRE · Vendor: siemens · sudo project

Last updated 2026-09-01 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-03 03:16 UTCPublished CVE record published
2026-09-01 13:19 UTCUpdated Record last modified

sudo project sudo UPGRADE

Affected: < 1.9.17 · 1.9.17 · 1.9.17 p1 · 1.9.17 p2

Fixed in: 1.9.17

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy sudo || rpm -q sudo || sudo --version

2. UPGRADE to 1.9.17 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade sudo

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade sudo

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

siemens sinec os UPGRADE

Affected: < 4.0

Fixed in: 4.0

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-35535?

sudo: upgrade to 1.9.17; sinec os: upgrade to 4.0. Exact commands for each OS are on this page.

Is CVE-2026-35535 being exploited?

CVE-2026-35535 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-35535 affect?

CVE-2026-35535 affects sudo, sinec os. Severity is high (CVSS 7.4). 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.

How urgent is CVE-2026-35535?

Priority 28/100. High severity

Software pages

Sudo vulnerabilities · Siemens vulnerabilities

References

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