CVE-2026-23878Network attack vector

Authenticated document disclosure via unbound storage identifier

Published Jan 19, 2026 · Updated Jan 19, 2026

Authorization bypass in HotCRP 3.1 allows remote authenticated users to download documents from any submission through the document API. PaperInfo::document queries PaperStorage using a user-controlled global storage identifier without binding the record to the requested paper. Any author with at least one submission can supply another submission's document identifier and read its PDFs and attachments; no modification or service interruption is reported.

CVSS severity6.5
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in HotCRP 3.1 allows remote authenticated users to download documents from any submission through the document API. PaperInfo::document queries PaperStorage using a user-controlled global storage identifier without binding the record to the requested paper. Any author with at least one submission can supply another submission's document identifier and read its PDFs and attachments; no modification or service interruption is reported.

The record

CVE
CVE-2026-23878
Published
Jan 19, 2026
Updated
Jan 19, 2026
Vendor
Eddie Kohler
Product
HotCRP
Classifications
CWE-639, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= aa20ef288828b04550950cf67c831af8a525f508, < ceacd5f1476458792c44c6a993670f02c984b4a0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Eddie Kohler · HotCRPversion=>= aa20ef288828b04550950cf67c831af8a525f508, < ceacd5f1476458792c44c6a993670f02c984b4a0

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
T1213Data from Information Repositories

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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