Unrated

Unauthorized attachment upload in Avo

IdentifiersCVE-2026-53769CWE-862

CVE-2026-53769 is an authorization flaw in Avo affecting the direct attachment upload endpoint. The endpoint does not enforce server-side upload authorization, allowing an authenticated user to bypass field-level upload policy checks and record update restrictions when adding or replacing attachments. In affected deployments, the vulnerable behavior permits attachment operations that should be denied by application policy, including direct upload flows and key-based or Trix-style attachment handling that result in blob creation and returned attachment references.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an authenticated attacker to modify protected record attachments without proper authorization. This can result in unauthorized replacement or addition of attachment content, storage of attacker-controlled files as application blobs, and integrity violations affecting records that the attacker should not be able to update. In workflows that return attachment references after upload, the flaw can also provide unauthorized access to usable attachment objects for subsequent abuse within the application.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, restrict access to Avo routes to fully trusted administrators only. As an interim control, override or monkey-patch the attachment upload controller logic to validate the target record and enforce upload authorization before blob creation, including equivalent authorization checks for key-based and Trix-related upload flows, and deny unauthorized requests with an HTTP 403 response.

Remediation

Patch, then assume compromise.

Upgrade the RubyGems package avo to version 3.32.0 or later, which corrects the missing authorization enforcement in the upload path.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

AvoAvoapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

No public activity tracked yet. Mallory keeps watching.

0 SOURCESView more in app

No public activity observed for this vulnerability.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity