High Memory corruption

CVE-2026-45084 — OpenSIPS: Denial of service in presence.handle_publish() from unchecked Content-Type state

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Versions 3.4.0 through 3.6.5 contain a denial of service vulnerability in the presence module. When the presence module's handle_publish() function processes a SIP PUBLISH request with an Event: presence header and a message body while the configuration option enable_sphere_check=1 is set, it invokes the get_content_type() macro without first calling parse_content_type_hdr(), causing it to dereference uninitialized or NULL Content-Type parsing state and crash. If a Content-Type header is present but unparsed, msg->content_type->parsed is NULL and is dereferenced as a content_t pointer; if the request lacks a Content-Type header entirely, msg->content_type itself is NULL, and both cases lead to a crash. A remote attacker can therefore cause a denial of service against an affected instance with a single PUBLISH request over UDP or TCP, using either a valid Content-Type: application/pidf+xml request or one with the header removed, and the vulnerable code path itself does not enforce authentication (though a deployment's routing configuration may require it before this route is reached). The issue has been fixed in version 3.6.6 and 4.0.0-rc1.

Published Aug 4, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

Technical severity (high)+6
CISA SSVC: exploitation "poc"+5
Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

—

No EPSS score.

Affects

OpenSIPS

CVSS base

8.7

High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Proof of concept

none · proof-of-concept · active

Automatable

Yes

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (OpenSIPS OpenSIPS).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
OpenSIPS	OpenSIPS	version >= 3.4.0, < 3.6.6version >= 4.0.0-beta, < 4.0.0-rc1	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Attack requirements

None

Privileges required

None

User interaction

None

Scope

Confidentiality (vulnerable system)

None

Integrity (vulnerable system)

None

Availability (vulnerable system)

High

Confidentiality (subsequent)

None

Integrity (subsequent)

None

Availability (subsequent)

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.7	CVSS 4.0	High	—	—	security-advisories@github.com via NIST National Vulnerability Database
8.7	CVSS 4.0	High	—	—	GitHub_M via CVE Program (cve.org) e CISA ADP

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

(score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-476 · NULL Pointer Dereference

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.

web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

2026
Affected products added · opensips/opensips
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
CVSS changed · 8.7
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Awaiting Analysis
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Aug 4, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

1 on the record

github.com/OpenSIPS/opensips/security/advisories/GHSA-h3ww-hchh-x2g9
x_refsource_CONFIRM, NIST National Vulnerability Database

Elsewhere on this site

OpenSIPS
every CVE for this vendor

Memory corruption
same class

CWE-476
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-45809 OpenSIPS: Denial of Service in watcherinfo XML generation from oversized watcher URI Aug 4, 2026
High CVE-2026-46334 OpenSIPS: Denial of Service in SDP bandwidth parsing via QoS SDP cloning Aug 4, 2026
Medium CVE-2026-45705 OpenSIPS: OOB Read in Multipart Body Boundary Parsing Aug 4, 2026
Critical CVE-2026-45537 OpenSIPS: Global Buffer Overflow in construct_uri Aug 4, 2026
Critical CVE-2026-45100 OpenSIPS: Buffer Overflow in Base64 Encode Transformation Aug 4, 2026
High CVE-2026-45103 OpenSIPS: SIP Message Smuggling via TCP Content-Length Integer Overflow Aug 4, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No FIRST EPSS score.
No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-45084 is "OpenSIPS: Denial of service in presence.handle_publish() from unchecked Content-Type state", rated High. It affects OpenSIPS (OpenSIPS); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.7 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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