vulnerability / NVI-00004639 / Revision 2
Grav: Origin validation bypass in Uri::referrer() and Pages::referrerRoute() via unanchored prefix match
OSV carries this publisher advisory for getgrav/grav. This is an aggregated source copy; consult the original publisher and compare update dates.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
5.4 MEDIUM (3.1)
disclosure@vulncheck.com severity; no combined Null risk score.
9.3 CRITICAL (4.0)
disclosure@vulncheck.com severity; no combined Null risk score.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
getgrav/grav
source listedECOSYSTEM: introduced 0; fixed 2.0.16
## Summary `Grav\Common\Uri::referrer()` and `Grav\Common\Page\Pages::referrerRoute()` both check whether an incoming request's `Referer` header "came from our site" using `str_starts_with($referrer, $base)`, where `$base` is the site's own absolute root URL (for example `https://example.com`, no trailing slash). Because the comparison has no boundary character after the prefix, any `Referer` value that merely starts with that string is accepted, including a `Referer` from a completely different host such as `https://example.com.attacker.tld`. This is the same class of bug already fixed once in 2.0.15 for the fast static asset server (GHSA-4v9q-p283-qc2m, "also allowing any neighbouring directory whose name starts with the same letters"). The identical pattern is still present in both places that trust the `Referer` header, and neither is covered by that fix. ## Affected product and version Product: Grav CMS, getgrav/grav Confirmed present in: 2.0.15, commit c2b46866857a93a0aa7048e7ed707ed3ed45dbc3 The pattern is not touched by any of the 2.0.15 security fixes, so earlier 2.x releases are likely affected too. I have not checked how far back it goes. ## Affected code `system/s
03 / Response
What to do next
- vendor patch
The original advisory lists fixed boundaries 2.0.16 for getgrav/grav. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. NIST National Vulnerability Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-9ccq-2jfg-qw33 ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
- CVE-2026-72702 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 2 ·
Source facts changed; compare the preserved prior revision.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.