Retrospective for 2026-08-18, compiled on 27 October 2026. The date identifies the day being analysed; source publication and revision dates are recorded below.
What this advisory changes in your environment
The starting point is CERTFR-2026-AVI-1036, published on 2026-08-18. Its scope includes typo3. Reported consequences are security control bypass. These statements apply to the advisory’s scope; they do not assign every consequence to every product or CVE.
This case focuses on typo3. Locate that edition in live installations, deployment images and actual dependencies, rather than treating every product from Typo3 as equivalent.
Products and versions to examine
- Reference
- CERTFR-2026-AVI-1036
- Source first published
- 2026-08-18
- Latest source revision available for this day
- 2026-08-18
- Named components
- typo3
- CVE identifiers
- CVE-2026-19418, CVE-2026-15305
| Component | Published condition |
|---|---|
| typo3 | 13.x : < 13.4.34 |
| typo3 | 14.x : < 14.3.6 |
For typo3, the published condition is “13.x : < 13.4.34”. Compare the version actually loaded with that condition within its own release branch. A fix installed on another edition of typo3 does not close this case.
Mechanism and prerequisites
A security bypass challenges a trust boundary. Verify server-side authorisation decisions and alternative paths; hiding an interface is not an access restriction.
The primary record CVE-2026-19418, published by TYPO3, covers TYPO3 CMS. The retained revision is dated 2026-08-11. Its scope is presented separately from the integrations and product groupings in CERTFR-2026-AVI-1036.
The published metric for CVE-2026-19418 is CVSS 4.0, 7.3/10. The vector below describes technical prerequisites; it does not measure attack frequency or the likelihood that your deployment is compromised.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- Attack vector
- network
- Prior privileges
- low
- User interaction
- active
- Complexity
- low
- Additional attack requirements
- present
- Weakness
- CWE-346, CWE-352
Choose the appropriate intervention
- Locate typo3 instances, running releases and service owners. Record condition 13.x : < 13.4.34 in the ticket alongside reference CERTFR-2026-AVI-1036.
- Compare the installed branch with the vendor’s typo3 release notes. Prepare the package for that branch and a dependent-service test, retaining the pre-change state.
- After changing typo3, capture the loaded version again and verify the workflow below. Any exception needs an owner, an exposure-reduction measure and an expiry date.
Verify the fix in a real workflow
Validation scenario to adapt for typo3: On a test copy of typo3, compare ordinary and administrative accounts on the same workflow. Check creation, reading and modification of a synthetic object, then inspect submitted-content rendering without exposing real data. This is a proposed defensive check, not a claim that testing was performed against third-party systems.
Limit of case CERTFR-2026-AVI-1036: this analysis replaces neither vendor prerequisites nor investigation of your logs. Only documented versions are reproduced; no attack date or victim is invented.
Questions specific to this case
Which condition should be checked for typo3?
Advisory CERTFR-2026-AVI-1036 states: typo3 — 13.x : < 13.4.34. Check the edition and running release; do not extend the published boundary to branches absent from the advisory.
Which prerequisites does record CVE-2026-19418 specify?
For CVE-2026-19418, the published vector is CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Verify those conditions on TYPO3 CMS before applying them to an integration named in CERTFR-2026-AVI-1036.
Sources and related reading
- CERT-FR · CERTFR-2026-AVI-1036
- Vendor and remediation · github.com
- Vendor and remediation · github.com
- CVE-2026-19418 · CNA
Practical guide : Software inventory: prepare for end of support
Explore the decision addressed in this case
Complete source advisory inventory
The article table may be an extract. These lists contain every affected-system entry and CVE in the specified advisory revision. They are not an inventory of your assets and do not map every CVE to every product.
Official source · CERTFR-2026-AVI-1036
Advisory revision : · Checked on :
Affected systems · 2
Original French wording is retained to avoid ambiguous translations of version conditions.
- typo3 versions 13.x antérieures à 13.4.34
- typo3 versions 14.x antérieures à 14.3.6