Is CVE-2009-1891 being actively exploited?

CVE-2009-1891 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2009-1891?

CVE-2009-1891 has a CVSS 2.0 base score of 7.1 (HIGH).

CVE-2009-1891

HIGH · CVSS 7.1EPSS 17.1%EU EUVD

The mod_deflate module in Apache httpd 2.2.11 and earlier compresses large files until completion even after the associated network connection is closed, which allows remote attackers to cause a denial of service (CPU consumption).

Key facts

CVSS score: 7.1 (v2.0)
Severity: HIGH
CVSS vector: AV:N/AC:M/Au:N/C:N/I:N/A:C
Weakness (CWE): CWE-400
EPSS score: 17.1% (97th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2009-1886)
Published: July 10, 2009
NVD last modified: June 16, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2009-1886 in the EU Vulnerability Database. Last updated in EUVD on August 7, 2024.

View on the EU Vulnerability Database

Affected products

apache / http server
canonical / ubuntu linux
canonical / ubuntu linux
canonical / ubuntu linux
canonical / ubuntu linux
debian / debian linux
debian / debian linux
debian / debian linux
fedoraproject / fedora
redhat / enterprise linux desktop
redhat / enterprise linux eus
redhat / enterprise linux server
redhat / enterprise linux server aus
redhat / enterprise linux workstation

Certified products that may be affected

1 FIPS 140 or Common Criteria certified product, from automated matching by sec-certs.org.

Red Hat Enterprise Linux 5 OpenSSH-Server Cryptographic Module - Red Hat®, Inc. - FIPS 140 1384 - historical

References

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=534712(Exploit)
http://lists.apple.com/archives/security-announce/2009/Nov/msg00000.html(Broken Link, Mailing List)
http://lists.opensuse.org/opensuse-security-announce/2009-10/msg00006.html(Mailing List, Third Party Advisory)
http://marc.info/?l=apache-httpd-dev&m=124621326524824&w=2(Exploit, Issue Tracking, Mailing List, Third Party Advisory)
http://marc.info/?l=apache-httpd-dev&m=124661528519546&w=2(Issue Tracking, Mailing List, Third Party Advisory)
http://marc.info/?l=bugtraq&m=129190899612998&w=2(Issue Tracking, Mailing List, Third Party Advisory)
http://marc.info/?l=bugtraq&m=130497311408250&w=2(Issue Tracking, Mailing List, Third Party Advisory)
http://osvdb.org/55782(Broken Link)
http://secunia.com/advisories/35721(Not Applicable, Vendor Advisory)
http://secunia.com/advisories/35781(Not Applicable, Vendor Advisory)
http://secunia.com/advisories/35793(Not Applicable, Vendor Advisory)
http://secunia.com/advisories/35865(Not Applicable, Vendor Advisory)
http://secunia.com/advisories/37152(Not Applicable, Vendor Advisory)
http://secunia.com/advisories/37221(Not Applicable, Vendor Advisory)
http://security.gentoo.org/glsa/glsa-200907-04.xml(Third Party Advisory)
http://support.apple.com/kb/HT3937(Broken Link)
http://wiki.rpath.com/Advisories:rPSA-2009-0142(Broken Link)
http://wiki.rpath.com/wiki/Advisories:rPSA-2009-0142(Broken Link)
http://www-01.ibm.com/support/docview.wss?uid=swg1PK91361(Third Party Advisory)
http://www-01.ibm.com/support/docview.wss?uid=swg1PK99480(Third Party Advisory)
http://www.debian.org/security/2009/dsa-1834(Third Party Advisory)
http://www.mandriva.com/security/advisories?name=MDVSA-2009:149(Broken Link, Patch)
http://www.redhat.com/support/errata/RHSA-2009-1156.html(Third Party Advisory)
http://www.securityfocus.com/archive/1/507857/100/0/threaded(Third Party Advisory, VDB Entry)
http://www.securitytracker.com/id?1022529(Broken Link, Third Party Advisory, VDB Entry)
http://www.ubuntu.com/usn/USN-802-1(Third Party Advisory)
http://www.vupen.com/english/advisories/2009/1841(Permissions Required, Vendor Advisory)
http://www.vupen.com/english/advisories/2009/3184(Permissions Required, Vendor Advisory)
https://bugzilla.redhat.com/show_bug.cgi?id=509125(Issue Tracking, Patch, Third Party Advisory)
https://lists.apache.org/thread.html/54a42d4b01968df1117cea77fc53d6beb931c0e05936ad02af93e9ac%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/5df9bfb86a3b054bb985a45ff9250b0332c9ecc181eec232489e7f79%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/8d63cb8e9100f28a99429b4328e4e7cebce861d5772ac9863ba2ae6f%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/f7f95ac1cd9895db2714fa3ebaa0b94d0c6df360f742a40951384a53%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r0276683d8e1e07153fc8642618830ac0ade85b9ae0dc7b07f63bb8fc%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r2cb985de917e7da0848c440535f65a247754db8b2154a10089e4247b%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r57608dc51b79102f3952ae06f54d5277b649c86d6533dcd6a7d201f7%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r5f9c22f9c28adbd9f00556059edc7b03a5d5bb71d4bb80257c0d34e4%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r75cbe9ea3e2114e4271bbeca7aff96117b50c1b6eb7c4772b0337c1f%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r7dd6be4dc38148704f2edafb44a8712abaa3a2be120d6c3314d55919%40%3Ccvs.httpd.apache.org%3E
https://lists.apache.org/thread.html/r84d043c2115176958562133d96d851495d712aa49da155d81f6733be%40%3Ccvs.httpd.apache.org%3E

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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