HIGH CVSS 7.3
Published: 2026-01-30

CVE-2026-25156

hotcrp hotcrp Security Advisory (CVE-2026-25156)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-25156 impacting hotcrp hotcrp. Evaluated with CVSS Base Score of 7.3 (HIGH).

Original NVD Description

Source: NIST NVD
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`.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
Low (PR:L)
Standard user access required
User Interaction
Required (UI:R)
User must click or open resource
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
High (C:H)
Total information disclosure
Integrity
High (I:H)
Total modification of target system
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product hotcrp / hotcrp
Affected Versions 3.2
Weakness Enumeration CWE-79

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2026-25156 impacting hotcrp hotcrp.

⚡ Nuclei Detection Template (YAML) cve-2026-25156.yaml
id: cve-2026-25156

info:
  name: hotcrp hotcrp - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-25156 affecting hotcrp hotcrp.
    Evaluation: HotCRP is conference review software. HotCRP versions from October 2025 through January 2026 delivered documents of all types with inline Content-Disp...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-25156
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
    cvss-score: 7.3
    cve-id: CVE-2026-25156
    cwe-id: CWE-79
  tags: cve,cve-2026-25156,hotcrp,hotcrp,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "hotcrp"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-25156.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-25156
# Target: hotcrp hotcrp | CVSS: 7.3 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-25156 (hotcrp hotcrp)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against hotcrp hotcrp scope (3.2).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2026-25156.sh
# Recommended Remediation & Patching Commands for CVE-2026-25156
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install hotcrp 2>/dev/null || \
sudo dnf upgrade hotcrp 2>/dev/null || \
sudo yum update hotcrp

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i hotcrp 2>/dev/null || rpm -qa | grep -i hotcrp

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-25156 in hotcrp hotcrp?

Review vendor-specific security notices and update hotcrp hotcrp packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2026-25156?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2026-25156?

CVE-2026-25156 is classified with a CVSS 3.1 Base Score of 7.3 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.3
HIGH SEVERITY
CVE ID CVE-2026-25156
Weakness CWE-79
Vendor hotcrp
Product hotcrp
Published 2026-01-30
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N