What is CVE-2023-27641?

CVE-2023-27641 is a medium-severity vulnerability in Lsoft Listserv, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2023-03-05.

How severe is CVE-2023-27641?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Is CVE-2023-27641 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Lsoft Listserv

CVE-2023-27641

The REPORT (after z but before a) parameter in wa.exe in L-Soft LISTSERV 16.5 before 17 allows an attacker to conduct XSS attacks via a crafted URL.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2023-03-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.011 (64.1th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 64.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Lsoft Listserv

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

References

github.com/hosakauk/exploits/blob/master/listserv_report_xss.MD (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2023-27641?: CVE-2023-27641 is a medium-severity vulnerability in Lsoft Listserv, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2023-03-05.
How severe is CVE-2023-27641?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2023-27641 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.