BaserCMS: Improper Neutralization of Formula Elements in a CSV File
CVE-2026-65875 is a high-severity improper neutralization of formula elements in a CSV file vulnerability in BaserCMS from baserCMS Users Community, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 5.3.0 as the first without the flaw, so updating BaserCMS to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.26% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update BaserCMS to 5.3.0 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| baserCMS Users Community | BaserCMS | before 5.3.0 | 5.3.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L. Scored by CNA (jpcert.or.jp).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 5.1 | Medium | CNA (jpcert.or.jp) |
| CVSS 3.1 | 7.1 | High | CNA (jpcert.or.jp) |
Official description
BaserCMS provided by baserCMS Users Community contains a CSV file injection vulnerability. If a user downloads and opens a CSV file containing malicious code injected by an attacker, the malicious code may be executed.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Formula Elements in a CSV File
The product saves user-provided information into a Comma-Separated Value (CSV) file, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as a command when the file is opened by a spreadsheet product.
How developers prevent this class of flaw
- When generating CSV output, ensure that formula-sensitive metacharacters are effectively escaped or removed from all data before storage in the resultant CSV. Risky characters include '=' (equal), '+' (plus), '-' (minus), and '@' (at).
- If a field starts with a formula character, prepend it with a ' (single apostrophe), which prevents Excel from executing the formula.
- Certain implementations of spreadsheet software might disallow formulas from executing if the file is untrusted, or if the file is not authored by the current user.
More Improper Neutralization of Formula Elements in a CSV File vulnerabilities (CWE-1236)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Improper Neutralization of Formula Elements in a CSV File vulnerabilities
- 7.3 High severity
- 8.8 High severity
- 8.8 High severity
- 9.8 Critical severity
- 8.8 High severity
- 7.8 High severity
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