CVE-2026-33738 — Lychee Vulnerable to Stored XSS via Photo Description in RSS/Atom/JSON Feed (No Sanitization on Public Endpoint)
Lychee is a free, open-source photo-management tool. Prior to version 7.5.3, the photo `description` field is stored without HTML sanitization and rendered using `{!! $item->summary !!}` (Blade unescaped output) in the RSS, Atom, and JSON feed templates. The `/feed` endpoint is publicly accessible without authentication, allowing any RSS reader to execute attacker-controlled JavaScript. Version 7.5.3 fixes the issue.
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
- EPSS 0.4% (30-day exploitation probability)+4
- Technical severity (medium)+3
- CISA SSVC: exploitation "poc"+5
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.
- Documented patch — github.com (NIST National Vulnerability Database)
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 (Lycheeorg Lychee).
- Apply the fixed version or the patch documented under Remediation.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes matching the vulnerability class (cross-site scripting), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
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 |
|---|---|---|---|---|---|
| 4.8 | CVSS 4.0 | Medium | — | — | security-advisories@github.com via NIST National Vulnerability Database |
| 4.8 | CVSS 4.0 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
| 5.4 | CVSS 3.1 | Medium | 2.3 | 2.7 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.36%
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 CSP violation reports and script payloads in reflected parameters.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · lycheeorg/lychee
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 5.4
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
4 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-77470 Lychee: Webshop checkout lets the client override the payment `amount` sent to the gateway via malicious crafted POST request 6h
- High CVE-2026-77466 Lychee: Webshop payment bypass via unrestricted "Dummy" gateway selection 6h
- High CVE-2026-77467 Lychee: A single 383-byte PDF causes ~184 seconds of CPU consumption in the real processing path 6h
- Medium CVE-2026-77468 Lychee: Missing Authentication for Critical Function and Allocation of Resources Without Limits or Throttling on /docs/api 6h
- High CVE-2026-62679 Lychee: Path traversal in `SecurePathController` allows authenticated arbitrary file read 6h
- High CVE-2026-61838 Lychee: Album password bypass in ZIP downloads 6h
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-2026-33738 is "Lychee Vulnerable to Stored XSS via Photo Description in RSS/Atom/JSON Feed (No Sanitization on Public Endpoint)", rated Medium. It affects Lychee (Lycheeorg); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.4 describes technical severity. EPSS 0.36% 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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