5.3

CVE-2026-33173: rails activestorage

CVSS: 5.3v4.0MediumAnalyzed
AliasesUBUNTU-CVE-2026-33173DEBIAN-CVE-2026-33173CGA-7mp5-8mcg-3qcg
Published 23-03-2026Last modified 24-03-2026
Open JSON

Vulnerability summary

CVE-2026-33173 is a medium (CVSS 5.3) vulnerability in rails activestorage. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 32.5% of scored vulnerabilities.

Overall risk
21/100
0100
Low · default modelHow is this calculated?
CVSS score
5.3/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.40%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CGA-JWMV-8X4W-7P4X

Timeline

  1. 23-03-2026
    PublishedVulnerability first disclosed.
  2. 24-03-2026
    Last modifiedVulnerability information updated.

Description

Active Storage allows users to attach cloud and local files in Rails applications. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, `DirectUploadsController` accepts arbitrary metadata from the client and persists it on the blob. Because internal flags like `identified` and `analyzed` are stored in the same metadata hash, a direct-upload client can set these flags to skip MIME detection and analysis. This allows an attacker to upload arbitrary content while claiming a safe `content_type`, bypassing any validations that rely on Active Storage's automatic content type identification. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.

CVSS metrics

9 scores · 7 sources · 2 versions

EPSS trend

Probability

0.40%

Chance of exploitation in the next 30 days

Percentile

33%

Versus all other CVEs

30-day change

+0.01 pp

From 0.39% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.40%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard26 products
  • gitlab-rails-ce-18.1All versions (No fix recorded)
  • gitlab-rails-ce-18.10< 18.10.3-r1
  • gitlab-rails-ce-18.2All versions (No fix recorded)
  • gitlab-rails-ce-18.3All versions (No fix recorded)
  • gitlab-rails-ce-18.4All versions (No fix recorded)
Debian1 product
  • rails< 2:6.1.7.10+dfsg-1~deb12u3 | < 2:7.2.2.2+dfsg-2~deb13u2 | < 2:7.2.3.1+dfsg-1
Rails1 product
  • activestorage≥ 8.1.0.beta1, < 8.1.2.1 | ≥ 8.0.0.beta1, < 8.0.4.1 | < 7.2.3.1
RubyGems1 product
  • activestorage≥ 8.1.0.beta1, < 8.1.2.1 | ≥ 8.0.0.beta1, < 8.0.4.1 | < 7.2.3.1
Rubyonrails1 product
  • rails< 7.2.3.1 | ≥ 8.0.0, < 8.0.4.1 | ≥ 8.1.0, < 8.1.2.1
Ubuntu1 product
  • railsAll versions (No fix recorded)
Wolfi1 product
  • ruby3.2-rails-8.1< 8.1.3-r0

7 vendors · 32 products

References

14 links
Show all 14 references