medium Known exploitedREV. 01

CVE-2025-35939Craft CMS — unauthenticated content lands in session files

Craft, the content management system (CMS), writes content from unauthenticated visitors into session files at a known path on the server. On its own that only stores the content; chained with a second flaw it becomes code.

YOUR NEXT MOVE

Upgrade Craft to 4.15.3 or 5.7.5 now; this is the first half of a chain, so patch the companion flaw in the same pass.

Read the risk

THE VITAL STATS
CVSS score
5.3/ 10
CVSS v3.1
EPSS probability
1%
Likelihood of exploitation
Attack complexity
Low
Conditions needed to exploit
Known exploited
Yes — CISA KEV
CVE published
2025-05-07
Added to KEV
2025-06-02
Exploit published
Not recorded
Confidence
high
Kill chain
unclassified
MITRE ATT&CK
—
Severity
medium

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Attacker needsNetwork access to the site; no credentials needed.

Fixed inCraft CMS 4.15.3, Craft CMS 5.7.5

Behind the card

4 REFERENCES
Field-level provenanceTRACE THE SOURCES +

Which source supports each field, when it was retrieved, and who extracted it.

FieldsSourceRetrievedExtractorConfidence
cvss, exploitation.attack_complexity, exploitation.exploit_available, references, published_atnvd.nist.gov2026-09-24scrty-crds-pipeline/0.1high
exploitation.known_exploited, exploitation.kev_addedcisa.gov2026-09-24scrty-crds-pipeline/0.1high
epssapi.first.org2026-09-24scrty-crds-pipeline/0.1high
title, summary, severity, remediation, mitre_attack, kill_chain, recommended_action, confidence, tags, exploitation.prerequisitesnvd.nist.gov2026-09-24claude-codehigh

Printing history

THE RECORD
  1. r1Initial base card

First printing. This card has not been reprinted since publication.

crds:cve-2025-35939 · CRDS 0.1 · Issued 2026-09-24