Hotcrp
CVE-2026-25156
HIGH
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessAuthenticated user uploads malicious HTML/SVG document
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DeliveryVictim clicks document link in HotCRP
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ExploitBrowser renders document inline instead of downloading
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ExecutionJavaScript executes in victim's browser context
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ImpactAttacker steals session cookies or sensitive data
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Output encoding, context-aware escaping
MITRE ATT&CK
2 techniques across 2 tactics: Initial Access, Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | HotCRP versions October 2025–January 2026 with inline Content-Disposition delivery enabled for non-PDF/image types. Requires authenticated user account (PR:L) and victim interaction (UI:R) to click document link. Vulnerable when HTML/SVG documents are delivered with inline disposition instead of attachment disposition. |
| Impact | CVSS 7.3 (HIGH). Attack vector: Network. Complexity: Low. Privileges required: Low. User interaction: Required. |
| Exploit ScenarioDerived | An attacker could exploit this vulnerability to compromise the affected system. |
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Alert meAnalysisAIv1 – Mar 12, 2026
HotCRP conference review software versions from October 2025 through January 2026 improperly render uploaded documents inline in the browser instead of forcing download, allowing malicious HTML or SVG files to execute JavaScript with access to user credentials and HotCRP API permissions. Attackers can exploit this stored XSS vulnerability by uploading crafted documents to submission fields, which then compromise any user who clicks the document link. A patch is available to restrict inline rendering to safe document types.
Earlier versions of this analysis (1)
HotCRP is conference review software. HotCRP versions from October 2025 through January 2026 delivered documents of all types with inline Content-Disposition, causing them to be rendered in the user’s browser rather than downloaded. [CVSS 7.3 HIGH]
RemediationAI
A vendor patch is available — apply it immediately. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Classified as CWE-79 (Cross-site Scripting (XSS)). Affects Hotcrp. HotCRP is conference review software. HotCRP versions from October 2025 through January 2026 delivered documents of all types with inline Content-Disposition, causing them to be rendered in the user’s browser rather than downloaded. (The intended behavior was for only text/plain, application/pdf, image/gif, image/jpeg, and image/png to be delivered inline, though adding save=0 to the document URL could request inline delivery for any document.) This made users who clicked a document
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
Primary rating from GitHub Advisory · only source for this CVE.
CVSS VectorGitHub Advisory
Lifecycle Timeline
2DescriptionGitHub Advisory
HotCRP is conference review software. HotCRP versions from October 2025 through January 2026 delivered documents of all types with inline Content-Disposition, causing them to be rendered in the user’s browser rather than downloaded. (The intended behavior was for only text/plain, application/pdf, image/gif, image/jpeg, and image/png to be delivered inline, though adding save=0 to the document URL could request inline delivery for any document.) This made users who clicked a document link vulnerable to cross-site scripting attacks. An uploaded HTML or SVG document would run in the viewer’s browser with access to their HotCRP credentials, and Javascript in that document could eventually make arbitrary calls to HotCRP’s API. Malicious documents could be uploaded to submission fields with “file upload” or “attachment” type, or as attachments to comments. PDF upload fields were not vulnerable. A search of documents uploaded to hotcrp.com found no evidence of exploitation. The vulnerability was introduced in commit aa20ef288828b04550950cf67c831af8a525f508 (11 October 2025), present in development versions and v3.2, and fixed in commit 8933e86c9f384b356dc4c6e9e2814dee1074b323 and v3.2.1. Additionally, c3d88a7e18d52119c65df31c2cc994edd2beccc5 and v3.2.1 remove support for save=0.
Executive ViewAI
HotCRP conference review systems deployed between October 2025 and January 2026 are vulnerable to document exposure attacks where files render in-browser instead of downloading, potentially exposing sensitive peer review content and confidential submission materials. Organizations using affected versions should prioritize patching to prevent unauthorized disclosure of competitive or proprietary information shared through the platform.
Apply vendor patch.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
Affected Products (CPE)GitHub Advisory
HotCRP conference review software version 3.1 has an inadequate input sanitization flaw (CVSS 9.9) that allows authentic
Authenticated HotCRP users can unmask the authors of anonymous reviews and comments by probing the `cmt:USER` search ter
HotCRP is conference review software. [CVSS 6.5 MEDIUM]
A vulnerability was found in HotCRP. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no au
NVD
CVE.org
EPSS
GitHub
Exploit-DB