CVE Intelligence
CISA KEV High File handling

CVE-2020-13671 — Drupal core Un-restricted Upload of File

Drupal core does not properly sanitize certain filenames on uploaded files, which can lead to files being interpreted as the incorrect extension and served as the wrong MIME type or executed as PHP for certain hosting configurations. This issue affects: Drupal Drupal Core 9.0 versions prior to 9.0.8, 8.9 versions prior to 8.9.9, 8.8 versions prior to 8.8.11, and 7 versions prior to 7.74.

Published Nov 20, 2020 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: drupal

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

CISA KEV · Jan 18, 2022 Proofs of concept on GitHub · 3
How the score was calculated
  • Confirmed exploitation (CISA KEV)+35
  • Public exploit/PoC (github)+6
  • EPSS 35.4% (30-day exploitation probability)+15
  • Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Confirmed
CISA KEV, listed Jan 18, 2022
EPSS FIRST
35.35%
ahead of 98% of scored CVEs · Oct 14, 2026
Affects
Drupal
Drupal and 4 more
CVSS base
8.8
High · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Active
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Composer Drupal/core: fixed in version 9.0.8 — github.com (GitHub Security Advisories)
  • Composer Drupal/core: fixed in version 8.9.9 — github.com (GitHub Security Advisories)
  • Composer Drupal/core: fixed in version 8.8.11 — github.com (GitHub Security Advisories)
  • Composer Drupal/core: fixed in version 7.74 — github.com (GitHub Security Advisories)
  • Composer Drupal/drupal: fixed in version 7.74 — github.com (GitHub Security Advisories)
  • Composer Drupal/drupal: fixed in version 8.8.11 — github.com (GitHub Security Advisories)
  • Composer Drupal/drupal: fixed in version 8.9.9 — github.com (GitHub Security Advisories)
  • Composer Drupal/drupal: fixed in version 9.0.8 — github.com (GitHub Security Advisories)

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: Jul 18, 2022 — passed 1550 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Drupal Drupal, Drupal Drupal core, Fedoraproject Fedora…).
  2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
  3. Apply the fixed version or the patch documented under Remediation.
  4. EPSS ahead of 98% of scored CVEs: prioritize it in the patch queue.
  5. Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Drupal Drupal ≥ 9.0.0 and < 9.0.8≥ 7.0 and < 7.74≥ 8.8.0 and < 8.8.11≥ 8.9.0 and < 8.9.9 Vulnerable NIST National Vulnerability Database
Drupal Drupal core version 9.0 versions prior to 9.0.8version 8.9 versions prior to 8.9.9version 8.8 versions prior to 8.8.11version 7 versions prior to 7.74 Vulnerable CVE Program (cve.org) e CISA ADP
Fedoraproject Fedora version 33version 32 Vulnerable NIST National Vulnerability Database
Composer Drupal/core ≥ 9.0.0 and < 9.0.8≥ 8.9.0 and < 8.9.9≥ 8.0.0 and < 8.8.11≥ 7.0.0 and < 7.74 Vulnerable GitHub Security Advisories
Composer Drupal/drupal ≥ 7.0.0 and < 7.74≥ 8.0.0 and < 8.8.11≥ 8.9.0 and < 8.9.9≥ 9.0.0 and < 9.0.8 Vulnerable GitHub Security Advisories

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
8.8 CVSS 3.1 High 2.8 5.9 nvd@nist.gov via NIST National Vulnerability Database
8.8 CVSS 3.1 High 2.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
8.8 CVSS 3.1 High — — GitHub, Inc. via GitHub Security Advisories
8.8 CVSS 3.1 High — — CISA-ADP via CVE Program (cve.org) e CISA ADP
6.5 CVSS 2.0 Medium 8.0 6.4 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-434 · Unrestricted Upload of File with Dangerous Type

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed
Jan 18, 2022
Federal deadline
Jul 18, 2022
passed 1550 day(s) ago
Ransomware use
Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Proofs of concept on GitHub

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 35.35%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Monitor file creation in web directories and paths with traversal sequences (../).
  • Hunt retroactively in logs from before Jan 18, 2022 (KEV listing): exploitation may have started earlier.
web/proxy/WAF logsnetwork IDS/IPSfile integrity (FIM)endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Fix documented
    Oct 13, 2026 · GitHub Security Advisories
  • Affected products added · composer/drupal/core, composer/drupal/drupal
    Oct 13, 2026 · GitHub Security Advisories
  • Affected products added · drupal/drupal core
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Affected products added · drupal/drupal, fedoraproject/fedora
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 8.8
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Added to CISA KEV (detected)
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Record created in this database
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • 2022
  • Added to CISA KEV catalog
    Jan 17, 2022 · CISA
  • 2020
  • CVE published
    Nov 20, 2020 · drupal

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 13, 2026 – Oct 13, 2026
  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

12 on the record

Elsewhere on this site

Drupal
every CVE for this vendor
2022-01
what else CISA listed that month
File handling
same class
CWE-434
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-55808 Drupal core - Moderately critical - Improper validation - SA-CORE-2026-009 Jul 10, 2026
  • CVE-2026-55804 Drupal core - Moderately critical - Gadget chain - SA-CORE-2026-006 Jul 10, 2026
  • CVE-2026-55806 Drupal core - Less critical - Cache poisoning and open redirect - SA-CORE-2026-007 Jul 10, 2026
  • CVE-2026-55807 Drupal core - Moderately critical - Server-side request forgery - SA-CORE-2026-008 Jul 10, 2026
  • CVE-2026-55803 Drupal core - Critical - PHP object injection - SA-CORE-2026-005 Jul 10, 2026
  • CVE-2026-54230 Abrt: event handler scripts follow symlinks when writing output files, allowing arbitrary file overwrites Jun 13, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2020-13671 is "Drupal core Un-restricted Upload of File", rated High. It affects Drupal (Drupal); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 8.8 describes technical severity. EPSS 35.35% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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