What is CVE-2009-2726?

CVE-2009-2726 is a vulnerability in Digium Asterisk, classified under Allocation of Resources Without Limits or Throttling. Published 2009-08-12.

Is CVE-2009-2726 known to be exploited?

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

Resource exhaustion in Digium Asterisk

CVE-2009-2726

The SIP channel driver in Asterisk Open Source 1.2.x before 1.2.34, 1.4.x before 1.4.26.1, 1.6.0.x before 1.6.0.12, and 1.6.1.x before 1.6.1.4; Asterisk Business Edition A.x.x, B.x.x before B.2.5.9, C.2.x before C.2.4.1, and C.3.x before C.3.1; and Asterisk Appliance s800i 1.2.x before 1.3.0.3 does not use a maximum width when invoking sscanf style functions, which allows remote attackers to cause a denial of service (stack memory consumption) via SIP packets containing large sequences of ASCII decimal characters, as demonstrated via vectors related to (1) the CSeq value in a SIP header, (2) large Content-Length value, and (3) SDP.

Published 2009-08-12 · last modified 2026-06-16.

CVSS v2 metric

CVSS v2 base score 7.8 (High). Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C. This CVE predates CVSS v3 and has no v3 score from NVD.

EPSS exploit prediction

EPSS: 0.065 (93.6th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 94th percentile — 93.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.065 · newest: 0.065 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

Public proof-of-concept exploits

ARPSyndicate/cve-scores

References

labs.mudynamics.com/advisories/MU-200908-01.txt (Broken Link)
www.vupen.com/english/advisories/2009/2229 (vdb-entry, Broken Link, Vendor Advisory)
downloads.digium.com/pub/security/AST-2009-005.html (Product)
www.securityfocus.com/bid/36015 (Exploit, VDB Entry, Third Party Advisory, vdb-entry, Broken Link)
www.securityfocus.com/archive/1/505669/100/0/threaded (mailing-list, VDB Entry, Third Party Advisory, Broken Link)
www.securitytracker.com/id (VDB Entry, Third Party Advisory, vdb-entry, Broken Link)
secunia.com/advisories/36227 (Broken Link, Vendor Advisory, third-party-advisory)

Frequently asked questions

What is CVE-2009-2726?: CVE-2009-2726 is a vulnerability in Digium Asterisk, classified under Allocation of Resources Without Limits or Throttling. Published 2009-08-12.
Is CVE-2009-2726 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.