CVE Intelligence
CISA KEV Critical Authentication exploit reference

CVE-2020-13927 — Apache Airflow's Experimental API Authentication Bypass

The previous default setting for Airflow's Experimental API was to allow all API requests without authentication, but this poses security risks to users who miss this fact. From Airflow 1.10.11 the default has been changed to deny all requests by default and is documented at https://airflow.apache.org/docs/1.10.11/security.html#api-authentication. Note this change fixes it for new installs but existing users need to change their config to default `[api]auth_backend = airflow.api.auth.backend.deny_all` as mentioned in the Updating Guide: https://github.com/apache/airflow/blob/1.10.11/UPDATING.md#experimental-api-will-deny-all-request-by-default

Published Nov 10, 2020 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, CVE Program (cve.org) e CISA ADP, NIST National Vulnerability Database, GitHub Security Advisories · CNA: apache

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 Detection templates (Nuclei) · 1Metasploit modules · 1Exploit-DB · 1
How the score was calculated
  • Confirmed exploitation (CISA KEV)+35
  • Public exploit/PoC (nuclei, metasploit, exploitdb)+20
  • EPSS 99.8% (30-day exploitation probability)+15
  • Technical severity (critical)+10
  • Automatable exploitation (SSVC)+3

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
99.78%
ahead of 100% of scored CVEs · Oct 15, 2026
Affects
Apache Software Foundation
Airflow and 1 more
CVSS base
9.8
Critical · 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
Yes
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.

  • Pip Apache-airflow: fixed in version 1.10.11 — github.com (GitHub Security Advisories)

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: Jul 18, 2022 — passed 1551 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 (Apache Software Foundation Airflow, Pip Apache-airflow).
  2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
  3. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  4. Apply the fixed version or the patch documented under Remediation.
  5. EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
  6. Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Apache Software Foundation Airflow < 1.10.11 Vulnerable NIST National Vulnerability Database
Pip Apache-airflow < 1.10.11 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
None
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
9.8 CVSS 3.1 Critical 3.9 5.9 nvd@nist.gov via NIST National Vulnerability Database
9.8 CVSS 3.1 Critical 3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
9.8 CVSS 3.1 Critical — — GitHub, Inc. via GitHub Security Advisories
9.8 CVSS 3.1 Critical — — CISA-ADP via CVE Program (cve.org) e CISA ADP
7.5 CVSS 2.0 High 10.0 6.4 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:N/AC:L/PR:N/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-306 · Missing Authentication for Critical Function

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 1551 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.

Detection templates (Nuclei)
Metasploit modules
Exploit-DB

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 15, 2026 · 3 reading(s) · max 99.78%

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).
  • Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.
  • Hunt retroactively in logs from before Jan 18, 2022 (KEV listing): exploitation may have started earlier.
web/proxy/WAF logsnetwork IDS/IPSauthentication logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Fix documented
    Oct 13, 2026 · GitHub Security Advisories
  • Affected products added · pip/apache-airflow
    Oct 13, 2026 · GitHub Security Advisories
  • Affected products added · apache/airflow
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · Published → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record published
    Oct 13, 2026
  • CVSS changed · 9.8
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Published
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • 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 10, 2020 · apache

Source activity

Repeated readings are counted rather than listed.

  • 3× 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

Apache Software Foundation
every CVE for this vendor
2022-01
what else CISA listed that month
Authentication
same class
CWE-306
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-86473 Apache Airflow: Logout ignores a presented Authorization bearer token, leaving it revocable only by expiry 24d
  • CVE-2026-82355 Apache Airflow: Session cookie silently overrides explicit Authorization bearer header, enabling session fixation 24d
  • CVE-2026-75158 Apache Airflow: Assets events API returns asset events for every Dag with no per-Dag authorization filter 24d
  • CVE-2026-75157 Apache Airflow: Asset queued-events DELETE endpoints gated on Dag READ instead of Dag EDIT (asset-triggered scheduling suppression) 27d
  • CVE-2026-68968 Apache Airflow: Authorization bypass in the Backfill API through conflicting interpretations of the backfill id Aug 12, 2026
  • CVE-2026-68969 Apache Airflow: Bulk Variable and Connection endpoints record secret values in the audit log in cleartext Aug 12, 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-2020-13927 is "Apache Airflow's Experimental API Authentication Bypass", rated Critical. It affects Airflow (Apache Software Foundation); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 9.8 describes technical severity. EPSS 99.78% 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.

Comments

Moderated technical discussion. Read the community guidelines.

No comments yet.

Sign in or create an account to comment and suggest corrections.