CVE-2025-62796 | PrivateBin persistent HTML injection in attachment filename enables redirect and defacement

PrivateBin is an online pastebin where the server has zero knowledge of pasted data. Versions 1.7.7 through 2.0.1 allow persistent HTML injection via the unsanitized attachment filename (attachment_name) when attachments are enabled. An attacker can modify attachment_name before encryption so that, after decryption, arbitrary HTML is inserted unescaped into the page near the file size hint, enabling redirect (e.g., meta refresh) and site defacement and related phishing attacks. Script execution is normally blocked by the recommended Content Security Policy, limiting confidentiality impact. The issue was introduced in 1.7.7 and fixed in 2.0.2. Update to 2.0.2 or later. Workarounds include enforcing the recommended CSP, deploying PrivateBin on a separate domain, or disabling attachments.

Published: 2025-10-28 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-62796 is rated Low Risk (29.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.27%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-62796

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.27% +0.23%
2 2025-10-29 0.03%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-62796

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 1.4 [email protected]

Weakness enumeration for CVE-2025-62796

GitHub Security Advisory for CVE-2025-62796

GHSA-867c-p784-5q6g · Severity: medium · Ecosystem: composer — PrivateBin is missing HTML sanitization of attached filename in file size hint

Affected software / configurations for CVE-2025-62796

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-62796

cvelogic Threat Intelligence