CVE-2019-18976

An issue was discovered in res_pjsip_t38.c in Sangoma Asterisk through 13.x and Certified...

7.5 HighFix available

An issue was discovered in res_pjsip_t38.c in Sangoma Asterisk through 13.x and Certified Asterisk through 13.21-x. If it receives a re-invite initiating T.38 faxing and has a port of 0 and no c line in the SDP, a NULL pointer dereference and crash will occur. This is different from CVE-2019-18940.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

12.8%Up 11.5 points since Apr 14, 2021

What each source reports

NVD Score used 7.5

Record: CVE-2019-18976
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Weakness: CWE-476
Updated: 2026-11-02

CVE List No score

Record: CVE-2019-18976
Updated: 2026-11-02

EUVDEUVD-2019-8638 No score

Record: EUVD-2019-8638
Updated: 2026-11-03

GitHub AdvisoriesGHSA-6fr3-g4mr-859f 7.5

An issue was discovered in res_pjsip_t38.c in Sangoma Asterisk through 13.x and Certified...

Record: GHSA-6fr3-g4mr-859f
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-476
Updated: 2026-11-02

OSV 7.5

Record: CVE-2019-18976
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2019-18976 7.5

Record: DEBIAN-CVE-2019-18976
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2019-18976 7.5

Record: UBUNTU-CVE-2019-18976
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`asterisk` Debian:14	before 1:16.1.1~dfsg-1, plus listed versions 0.1.11-30.1.11-3woody11:1.0.5-21:1.0.5-41:1.0.6-1 Show 45 moreShow less 1:1.0.6-21:1.0.7-11:1.0.7.dfsg.1-11:1.0.7.dfsg.1-21:1.0.7.dfsg.1-2sarge11:1.0.7.dfsg.1-2sarge21:1.0.7.dfsg.1-2sarge31:1.0.7.dfsg.1-2sarge41:1.0.7.dfsg.1-2sarge51:1.0.7.dfsg.1-2sarge61:1.0.9.dfsg-11:1.0.9.dfsg-31:1.0.9.dfsg-41:1.0.9.dfsg-51:1.0.9.dfsg-61:1.2.0-beta1.dfsg-11:1.2.0-beta2.dfsg-11:1.2.0-beta2.dfsg-21:1.2.0-beta2.dfsg-31:1.2.0-rc1.dfsg-11:1.2.0-rc2.dfsg-11:1.2.0.dfsg-11:1.2.0.dfsg-21:1.2.0.dfsg-31:1.2.0.dfsg-41:1.2.0.dfsg-51:1.2.0.dfsg-61:1.2.1.dfsg-11:1.2.1.dfsg-21:1.2.1.dfsg-31:1.2.10.dfsg-11:1.2.10.dfsg-1bpo11:1.2.10.dfsg-21:1.2.10.dfsg-31:1.2.11.dfsg-11:1.2.12.1.dfsg-11:1.2.13~dfsg-11:1.2.13~dfsg-21:1.2.13~dfsg-2etch11:1.2.13~dfsg-2etch21:1.2.13~dfsg-2etch31:1.2.13~dfsg-2etch41:1.2.14~dfsg-11:1.2.14~dfsg-21:1.2.14~dfsg-3	1:16.1.1~dfsg-1
`asterisk` Debian:9 From an advisory covering 5 CVEs	before 1:13.14.1~dfsg-2+deb9u6, plus listed versions 1:13.14.1~dfsg-21:13.14.1~dfsg-2+deb9u11:13.14.1~dfsg-2+deb9u21:13.14.1~dfsg-2+deb9u31:13.14.1~dfsg-2+deb9u41:13.14.1~dfsg-2+deb9u5	1:13.14.1~dfsg-2+deb9u6
`asterisk` Ubuntu:Pro:16.04:LTS	All versions, plus listed versions 1:13.1.0~dfsg-1.1ubuntu31:13.1.0~dfsg-1.1ubuntu41:13.1.0~dfsg-1.1ubuntu4.11:13.1.0~dfsg-1.1ubuntu4.1+esm1	None known
`asterisk` Ubuntu:18.04:LTS	All versions, plus listed versions 1:13.17.2~dfsg-1ubuntu11:13.17.2~dfsg-2ubuntu11:13.18.1~dfsg-1ubuntu11:13.18.3~dfsg-1ubuntu11:13.18.3~dfsg-1ubuntu21:13.18.3~dfsg-1ubuntu31:13.18.3~dfsg-1ubuntu4	None known

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2019-18976 is a high vulnerability (CVSS 7.5) in Digium Asterisk, published November 22, 2019. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 12.8%, the 96th percentile. Fixed in asterisk 1:16.1.1~dfsg-1.

References

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This page doesn't list everything

Left out here: 178 versions. The JSON record has them.