How severe is CVE-2026-39864?

CVE-2026-39864 has a CVSS 3.x base score of 4.4, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-39864 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-39864?

CVE-2026-39864 affects Kamailio. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-39864?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-39864 have an EU (EUVD) identifier?

Yes. CVE-2026-39864 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20617.

When was CVE-2026-39864 published?

CVE-2026-39864 was published on 2026-04-08 and last updated on 2026-06-17.

CVE-2026-39864

CVE-2026-39864 is a medium-severity vulnerability in Kamailio with a CVSS 3.x base score of 4.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Severity: Medium (CVSS 3.x base score 4.4)
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-20617
Weakness: CWE-125
Affected product: Kamailio
Published: 2026-04-08
Last modified: 2026-06-17

Description

Kamailio is an open source implementation of a SIP Signaling Server. Prior to 6.0.5 and 5.8.7, an out-of-bounds read in the auth module of Kamailio (formerly OpenSER and SER) allows remote attackers to cause a denial of service (process crash) via a specially crafted SIP packet if a successful user authentication without a database backend is followed by additional user identity checks. This vulnerability is fixed in 6.0.5 and 5.8.7.

Frequently asked questions

What is CVE-2026-39864?: Kamailio is an open source implementation of a SIP Signaling Server. Prior to 6.0.5 and 5.8.7, an out-of-bounds read in the auth module of Kamailio (formerly OpenSER and SER) allows remote attackers to cause a denial of service (process crash) via a specially crafted SIP packet if a successful user authentication without a database backend is followed by additional user identity checks. This vulnerability is fixed in 6.0.5 and 5.8.7.
How severe is CVE-2026-39864?: CVE-2026-39864 has a CVSS 3.x base score of 4.4, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-39864 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-39864?: CVE-2026-39864 affects Kamailio. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-39864?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-39864 have an EU (EUVD) identifier?: Yes. CVE-2026-39864 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20617.
When was CVE-2026-39864 published?: CVE-2026-39864 was published on 2026-04-08 and last updated on 2026-06-17.

References

https://github.com/kamailio/kamailio/security/advisories/GHSA-6m86-m342-g48m

Affected products (1)

cpe:2.3:a:kamailio:kamailio:*:*:*:*:*:*:*:*

More vulnerabilities in Kamailio

CVE-2020-27507 — Critical (CVSS 9.8): The Kamailio SIP before 5.5.0 server mishandles INVITE requests with duplicated fields and overlength tag, leading to a…
CVE-2018-16657 — Critical (CVSS 9.8): In Kamailio before 5.0.7 and 5.1.x before 5.1.4, a crafted SIP message with an invalid Via header causes a segmentation…
CVE-2018-14767 — Critical (CVSS 9.8): In Kamailio before 5.0.7 and 5.1.x before 5.1.4, a crafted SIP message with a double "To" header and an empty "To" tag…
CVE-2018-8828 — Critical (CVSS 9.8): A Buffer Overflow issue was discovered in Kamailio before 4.4.7, 5.0.x before 5.0.6, and 5.1.x before 5.1.2. A…
CVE-2013-7426 — Critical (CVSS 9.8): Insecure Temporary file vulnerability in /tmp/kamailio_fifo in kamailio 4.0.1.
CVE-2016-2385 — Critical (CVSS 9.8): Heap-based buffer overflow in the encode_msg function in encode_msg.c in the SEAS module in Kamailio (formerly OpenSER…

All CVEs affecting Kamailio →

Other CWE-125 (Out-of-bounds Read) vulnerabilities

CVE-2026-24826 — Critical (CVSS 10.0): Out-of-bounds Write, Divide By Zero, NULL Pointer Dereference, Use of Uninitialized Resource, Out-of-bounds Read,…
CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…

Browse all CWE-125 (Out-of-bounds Read) vulnerabilities →