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ExploitedNot in CISA KEV yet

CVE-2020-11991

Exploitation confirmed. First attested on 2023-10-14 by GCVE · kevintel, GCVE · shadowserver.

  • Published2020-09-11
  • WeaknessCWE-611

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

When using the StreamGenerator, the code parse a user-provided XML. A specially crafted XML, including external system entities, could be used to access any file on the server system.

Timeline

dates in UTC
  1. 2020-09-1114:15CVE publishedNVD
  2. 2023-10-1414:56Listed as exploited by GCVEGCVE
  3. 2023-10-1414:56Exploitation first reportedGCVE

Observed activity

isMalicious corpus · updated 2026-11-03 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-11991?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-11991?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Apache cocoon
BranchAffectedFixed in
2.1≥ 2.1, ≤ 2.1.12no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

Detection

read 2026-11-03 22:42 UTC
Nuclei template
available
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

Sources

  • GCVEexploitation2023-10-14
  • NVDCVSS 3.17.5read 2026-10-23
  • NVDCVSS 2.05read 2026-10-23
  • NVDweakness (CWE)CWE-611read 2026-10-23
  • FIRST EPSSEPSS score72.5 %read 2026-11-03
  • ProjectDiscoverydetectionread 2026-11-03

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Published
2020-09-11
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2020-11991?

When using the StreamGenerator, the code parse a user-provided XML. A specially crafted XML, including external system entities, could be used to access any file on the server system.

Is CVE-2020-11991 actively exploited?

Active exploitation of CVE-2020-11991 has not been confirmed. Its EPSS score was 72.5% on 2026-11-03, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-11991?

CVE-2020-11991 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

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