CVE-2026-42844: Grav is a file-based Web platform

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HIGH 8.8DOWNGRADE

CVE-2026-42844 is a high-severity flaw (CVSS 8.8) 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. In Grav 2.0.0-beta.2, a low-privileged authenticated API user with api.media.write can abuse /api/v1/blueprint-upload to write an arbitrary YAML file into user/accounts/, then log in as the newly created account with api.super privileges. This results in full administrative compromise of the Grav API. This vulnerability is fixed in API 1.0.0-beta.17.

Why this priority

High severity
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 73%)
CISA exploited list	No
Weakness	CWE-269, CWE-434
Published	2026-05-12
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

2026-05-12 22:16 UTCPublished CVE record published
2026-10-26 14:10 UTCUpdated Record last modified

getgrav grav DOWNGRADE

Affected: 2.0.0 beta2

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.0.0 (Debian / Ubuntu)

apt-cache madison grav sudo apt install grav=<VERSION_BEFORE_2.0.0> sudo apt-mark hold grav

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list grav sudo dnf downgrade grav-<VERSION_BEFORE_2.0.0> sudo dnf versionlock add grav

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2026-42844?

grav: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-42844 being exploited?

CVE-2026-42844 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-2026-42844 affect?

CVE-2026-42844 affects grav. Severity is high (CVSS 8.8). Grav is a file-based Web platform. In Grav 2.0.0-beta.2, a low-privileged authenticated API user with api.media.write can abuse /api/v1/blueprint-upload to write an arbitrary YAML file into user/accounts/, then log in as the newly created a

How urgent is CVE-2026-42844?

Priority 42/100. High severity; Public exploit reference

Related CVEs

CVE-2026-59193 MEDIUM 4.9 UPGRADE Grav is a file-based Web platform
CVE-2025-66844 CRITICAL 9.1 UPGRADE In grav <1.7.49.5, a SSRF (Server-Side Request Forgery) vector may be triggered via Twig templates when page c

References

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