CVE-2021-20787
Cross-site scripting vulnerability in GroupSession (GroupSession Free edition from ver2.2.0 to the version prior to ver5.1.0, GroupSession byCloud from ver3.0.3 to the version prior to ver5.1.0, and GroupSession ZION from ver3.0.3 to the version prior…
Does this matter?
Lower severity and a low EPSS score (0.64%). Track it; it rarely justifies an emergency change on its own.
Description
Cross-site scripting vulnerability in GroupSession (GroupSession Free edition from ver2.2.0 to the version prior to ver5.1.0, GroupSession byCloud from ver3.0.3 to the version prior to ver5.1.0, and GroupSession ZION from ver3.0.3 to the version prior to ver5.1.0) allows a remote attacker to inject an arbitrary script by sending a specially crafted request to a specific URL.
- CVSS 3.1
- 4.8 MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 0.64% probability · 50th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Affected
- groupsession/groupsession · groupsession/groupsession bycloud · groupsession/groupsession zion
- Source
- vultures@jpcert.or.jp
EPSS 0.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://groupsession.jp/info/info-news/security202107Vendor Advisory
- https://jvn.jp/en/jp/JVN86026700/index.htmlThird Party Advisory
- https://groupsession.jp/info/info-news/security202107Vendor Advisory
- https://jvn.jp/en/jp/JVN86026700/index.htmlThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.