CVE-2026-13602 — Session takeover vulnerability
We found a chain of combining multiple weaknesses in the product that could allow an attacker to become any user in the backend and access any data: * The payment integration plugins Stripe (included in the core system), pretix-mollie, pretix-oppwa, pretix-bitpay, pretix-payone, pretix-secuconnect, pretix-sofort, and pretix-saferpay contain a code path that is intended for the transport of session parameters from a tab with isolated cookies (e.g. in the pretix widget) to a new tab. For this purpose, a set of session parameters is cryptographically signed and then passed to the new tab as a URL parameter. The plugins perform no further validation of the session parameters, other than the cryptographic signature being valid. This is fixed with the releases issued today by strictly validating that no session parameters outside of the scope of the respective plugin may be set. * An unrelated feature in the core system is used to generate redirect links that obfuscate any Referer headers for outgoing links to prevent leakage of secrets in URLs. This redirect page also requires cryptographically signed parameters. Unfortunately, it uses the same key and salt for the signature as the previously mentioned feature in the payment integration plugins. A motivated attacker with access to at least one event in the backend can trick the system into cryptographically signing arbitrary content using specially crafted links. In combination with the previous issue, the attacker could use this to set and modify arbitrary parameters on their user session by injecting the signed parameters into the feature of the payment providers. This is fixed with the releases issued today by using different salts for the signature for each plugin and feature. * A third, unrelated feature in the core system is used for admin users to act on behalf of another user, mostly for debugging purposes. With being able to insert arbitrary parameters into a session, an attacker can abuse this feature to change their session from their actual user to any user in the system by guessing a valid user ID. This is fixed with the release today by requiring unguessable information to be contained in the session of the user to switch to.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- 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.
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.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
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.
- Identify exposed assets running the affected vendor/product/version combinations (Pretix Pretix, Pretix Pretix-bitpay, Pretix Pretix-mollie…).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (input validation), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Pretix | Pretix | ≥ 4.14.0 and < 2026.3.5≥ 2026.4.0 and < 2026.4.5≥ 2026.5.0 and < 2026.5.3 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Pretix | Pretix-bitpay | < 1.5.3 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Pretix | Pretix-mollie | < 2.5.7 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Pretix | Pretix-oppwa | < 1.4.4 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Pretix | Pretix-payone | < 1.4.3 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Pretix | Pretix-saferpay | < 1.6.3 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Pretix | Pretix-secuconnect | < 1.0.4 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Pretix | Pretix-sofort | < 1.4.2 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.7 | CVSS 4.0 | High | — | — | 655498c3-6ec5-4f0b-aea6-853b334d05a6 via NIST National Vulnerability Database |
| 7.7 | CVSS 4.0 | High | — | — | rami.io via CVE Program (cve.org) e CISA ADP |
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (score shown at the top: 655498c3-6ec5-4f0b-aea6-853b334d05a6) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
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).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · pretix/pretix, pretix/pretix-mollie, pretix/pretix-oppwa, pretix/pretix-bitpay, pretix/pretix-payone, pretix/pretix-secu
- SSVC assessment updated
- Record published
- CVSS changed · 7.7
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
1 on the record
Elsewhere on this site
Related CVEs (same products)
- Low CVE-2026-18028 Missing authorization check in event quick setup view Jul 28, 2026
- Critical CVE-2026-13603 SSRF with API key leak in pretix-oppwa Jul 1, 2026
- Medium CVE-2026-57536 Insufficient validation of payment status in pretix-mollie Jun 25, 2026
- Low CVE-2026-57533 Malicious HTML content could be injected into the page pretix shows when redirection to… Jun 25, 2026
- High CVE-2026-57532 Malicious HTML content contained in the layout specification of a PDF ticket or badge… Jun 25, 2026
- Low CVE-2026-57535 Content injected to PDF rendering contexts could, in many places, include HTML content… Jun 25, 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 FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- 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-2026-13602 is "Session takeover vulnerability", rated High. It affects Pretix (Pretix); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.7 describes technical severity. 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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