CVE
magento-lts token theft via OAuth callback URL allowlist bypass
Affects OpenMage magento-lts before 20.18.2 and 21.x before 21.0.0-beta3. Fixed in 20.18.2 and 21.0.0-beta3.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 20.18.2, 21.0.0-beta3
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Affected OpenMage magento-lts versions: before 20.18.2, and 21.x before 21.0.0-beta3. Attacker must hold the consumer key and secret. A logged-in administrator or customer must approve the authorize screen.
- Published
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 17/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
OpenMage magento-lts before 20.18.2 and 21.x before 21.0.0-beta3 validates OAuth 1.0a oauth_callback URLs with a string-prefix check and falls back to accepting any well-formed URL. Attackers holding a leaked consumer key and secret can supply host-suffix, userinfo, or arbitrary callback URLs to capture an approving administrator's or customer's request token and verifier, then obtain an access token with the victim's API privileges.
Who should check
Teams running OpenMage magento-lts before 20.18.2 or 21.x before 21.0.0-beta3 that issue OAuth 1.0a consumer credentials for REST API access.
Read the source excerpt
“OpenMage magento-lts before 20.18.2 and 21.x before 21.0.0-beta3”
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure8/25Specific setups only, reachable over the network
- Reach?/20Unknown. No tracked technology or package matched
- Severity8.7/10CVSS 8.7
- No patch0/5No signal
What would change the score
- Would score about 67 if added to CISA KEV
- Would score about 62 if CISA's SSVC rates exploitation active
- Would score about 24 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
Affected OpenMage magento-lts versions: before 20.18.2, and 21.x before 21.0.0-beta3. Attacker must hold the consumer key and secret. A logged-in administrator or customer must approve the authorize screen.Upgrade to a fixed version: 20.18.2, 21.0.0-beta3.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-128044 (OpenMage magento-lts before 20.18.2 OAuth Callback URL Allowlist Bypass), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-128044 (entry last updated 2026-11-13):
Affected:
- OpenMage magento-lts: fixed in 20.18.2
- OpenMage magento-lts: from 21.0.0-beta1, fixed in 21.0.0-beta3
Fixed versions: 20.18.2, 21.0.0-beta3.
Conditions (all must be true for the bug to be hit):
- Affected OpenMage magento-lts versions: before 20.18.2, and 21.x before 21.0.0-beta3. (source: https://www.vulncheck.com/advisories/openmage-magento-lts-before-20.18.2-oauth-callback-url-allowlist-bypass)
- Attacker must hold the consumer key and secret. (source: https://github.com/OpenMage/magento-lts/security/advisories/GHSA-mffc-h5pf-6f42)
- A logged-in administrator or customer must approve the authorize screen. (source: https://github.com/OpenMage/magento-lts/security/advisories/GHSA-mffc-h5pf-6f42)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, low-privilege login, a user action.
CISA KEV: CVE-2026-128044 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-128044 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/OpenMage/magento-lts/security/advisories/GHSA-mffc-h5pf-6f42
- https://github.com/OpenMage/magento-lts/commit/d03a00b60e4a2d4e5a00b44dbc66d25bc3b3fc8f
- https://www.vulncheck.com/advisories/openmage-magento-lts-before-20.18.2-oauth-callback-url-allowlist-bypass
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-128044
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-128044"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- OpenMage magento-lts
fixed in 20.18.2
- OpenMage magento-lts
From 21.0.0-beta1 · fixed in 21.0.0-beta3
Evidence 5
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-128044
Is CVE-2026-128044 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
The OAuth callback URL allowlist can be bypassed. An attacker who holds the consumer key and secret can capture an approving administrator's or customer's request token and verifier, then obtain an access token with the victim's API privileges.Source: vulncheck.com, github.com
Which versions are affected by CVE-2026-128044?
magento-lts: before 20.18.2. magento-lts: from 21.0.0-beta1 before 21.0.0-beta3.Source: cve.now feed data
Am I affected, and how do I check?
Versions of OpenMage magento-lts before 20.18.2, and 21.x versions before 21.0.0-beta3. The attack also requires that a logged-in administrator or customer approves the OAuth authorize screen. Compare the installed magento-lts version against these ranges.Source: vulncheck.com, github.com
How do I fix CVE-2026-128044?
Upgrade to 20.18.2 on the 20.x line or to 21.0.0-beta3 on the 21.x line.Source: vulncheck.com, github.com