Home/CVE/Craft CMS is a content management system (CMS). Versions 5.0.0-RC1 through 5.9.20, and 4.0.0-RC1 through 4.17.13 contain
CVE

CVE-2026-50283

Craft CMS is a content management system (CMS). Versions 5.0.0-RC1 through 5.9.20, and 4.0.0-RC1 through 4.17.13 contain

Craft CMS is a content management system (CMS). Versions 5.0.0-RC1 through 5.9.20, and 4.0.0-RC1 through 4.17.13 contain an authorization issue in the AssetsController::actionReplaceFile that can delete a source asset without source delete permission by supplying both assetId and sourceAssetId. AssetsController::actionReplaceFile() supports replacing a target asset file using another existing asset as the source.

The action loads: assetId - $assetToReplace and sourceAssetId - $sourceAsset, then enforces replace permissions using ($assetToReplace ?: $sourceAsset). When both IDs are provided, this expression resolves to the target asset so no permission check is performed against the source asset volume. When both assets are present, Craft copies the source file into the target and then deletes the source asset.

There is no deletion check for the source asset. An authenticated user who can replace files in one volume can delete assets in another volume where they do not have delete permission, as long as they can obtain a sourceAssetId, leading to broken content references and data loss. This issue has been fixed in versions 4.17.14 and 5.9.21.

EPSS 0.00265
EPSS exploitation odds0.27% · top 82%
Monitor
  • ⚠ NVD has not scored this CVE yet - manual triage required (common for recent CVEs)
Look this up elsewhere - one-click external pivots
How to read a CVE - triage first, then detect and patch
This page is every public fact about CVE-2026-50283, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.
Triage: should I act now? Four signals, and they are not interchangeable:
CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked. EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal. CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score. Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.
How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.
Then what - two workflows:
Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits. PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.
Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).

Severity & exploitation scoring

EPSS exploitation probability
0.27%
Top 82%odds of exploitation in the next 30 days
CVSS metric silhouette
No structured CVSS vector for this CVE. Older entries often have only a numeric base score - the metric breakdown radar requires a full AV:_/AC:_/... vector string published by NVD.
SSVC triage
No SSVC vulnrichment for this CVE. CISA's Vulnrichment program scores newer CVEs (~2024 onwards) plus selected older critical ones. Use the EPSS probability + KEV status to triage instead.

ATT&CK techniques

3

Techniques this CVE enables. Pills with a solid outline are high confidence - named directly in ATT&CK or Nuclei, or human-curated by CTID; the rest are inferred from the weakness type using MITRE's CVE Mapping Methodology and the CWE → CAPEC chain. Broad, generic-weakness guesses are filtered out. A small marks a technique that N independent sources agree on.

▤ Build a SIEM detection for these techniques

CAPEC attack patterns

1

Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.

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References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.