CVE-2026-42608: Grav is a file-based Web platform

Q: How do I fix CVE-2026-42608?

grav: upgrade to 2.0.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-42608 being exploited?

CVE-2026-42608 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-2026-42608 affect?

CVE-2026-42608 affects grav. Severity is critical (CVSS 9.1). Grav is a file-based Web platform. Prior to 2.0.0-beta.2, there is a Path Traversal vulnerability within the FormFlash core component. By manipulating the session_id (passed as __form-flash-id in POST requests), an unauthenticated attacker

Q: How urgent is CVE-2026-42608?

Priority 54/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

CRITICAL 9.1REMOTEUPGRADE

CVE-2026-42608 is a critical-severity flaw (CVSS 9.1) affecting grav. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Grav is a file-based Web platform. Prior to 2.0.0-beta.2, there is a Path Traversal vulnerability within the FormFlash core component. By manipulating the session_id (passed as __form-flash-id in POST requests), an unauthenticated attacker can traverse the filesystem to create arbitrary directories and write an index.yaml file containing attacker-controlled data. This vulnerability can lead to unauthorized modification of application behavior, po

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 51%)
CISA exploited list	No
Weakness	CWE-22
Published	2026-05-11
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: getgrav

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-11 16:17 UTCPublished CVE record published
2026-10-26 18:10 UTCUpdated Record last modified

getgrav grav UPGRADE

Affected: < 2.0.0 · 2.0.0 beta1

Fixed in: 2.0.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 2.0.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade grav

Note

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

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-2026-42608?

grav: upgrade to 2.0.0. Exact commands for each OS are on this page.

Is CVE-2026-42608 being exploited?

CVE-2026-42608 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-2026-42608 affect?

CVE-2026-42608 affects grav. Severity is critical (CVSS 9.1). Grav is a file-based Web platform. Prior to 2.0.0-beta.2, there is a Path Traversal vulnerability within the FormFlash core component. By manipulating the session_id (passed as __form-flash-id in POST requests), an unauthenticated attacker

How urgent is CVE-2026-42608?

Priority 54/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-42609 HIGH 8.1 UPGRADE Grav is a file-based Web platform
CVE-2026-42611 HIGH 8.9 UPGRADE Grav is a file-based Web platform
CVE-2026-42612 HIGH 8.5 UPGRADE Grav is a file-based Web platform
CVE-2026-44738 HIGH 7.7 UPGRADE Grav is a file-based Web platform
CVE-2026-42610 MEDIUM 6.5 UPGRADE Grav is a file-based Web platform

References

← Back to latest CVEs