VulnerabilityPublished 20 Mar 2026

CVE-2026-33069: pjsip pjproject · Out-of-bounds Read

Affects pjsip pjprojectSource CVE Database V5

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Not known to be exploited · CVSS 6.9 Medium : upgrade to 2.17 when convenient.

Data as of 1 Nov 2026, 22:58 UTC

CVSS 4.0 base score

6.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.17

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 1 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade pjproject and pjsip/pjproject to 2.17.

Affected software

Product	Affected	Fixed in
pjsippjproject	Affected <2.17	Fixed in 2.17
GitHubpjsip/pjproject`pkg:github/pjsip/pjproject`Other threats	Affected <2.17	Fixed in 2.17

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2026-33069, organizations should upgrade all instances of pjproject to version 2.17 or later, where the vulnerability is fixed. If immediate upgrading is not feasible, applying custom patches that add boundary checks after advancing the pointer in pjsip_multipart_parse() can reduce risk. Network-level mitigations include deploying SIP-aware intrusion detection and prevention systems (IDS/IPS) to detect and block malformed multipart SIP messages that could trigger the vulnerability. Restricting SIP traffic to trusted sources and implementing strict SIP message validation can reduce exposure. Monitoring logs for unusual SIP multipart message patterns may help identify exploitation attempts. Additionally, organizations should audit all applications and devices using pjproject for SIP processing to ensure they are updated. Regular security assessments and penetration testing focusing on SIP message handling can help detect residual risks. Finally, applying network segmentation to isolate VoIP infrastructure limits attacker lateral movement if exploitation occurs.

Description

PJSIP is a free and open source multimedia communication library written in C. Versions 2.16 and below have a cascading out-of-bounds heap read in pjsip_multipart_parse(). After boundary string matching, curptr is advanced past the delimiter without verifying it has not reached the buffer end. This allows 1-2 bytes of adjacent heap memory to be read. All applications that process incoming SIP messages with multipart bodies or SDP content are potentially affected. This issue is resolved in version 2.17.

Impact

The primary impact of CVE-2026-33069 is the potential disclosure of sensitive information due to out-of-bounds heap reads. Attackers can remotely send crafted SIP messages with multipart bodies to vulnerable systems, causing them to leak 1-2 bytes of adjacent heap memory. Although the amount of leaked data per request is small, repeated exploitation could allow attackers to piece together sensitive information such as cryptographic material, session tokens, or other in-memory data, undermining confidentiality. This could facilitate further attacks like session hijacking or credential theft. The vulnerability does not directly affect system integrity or availability, but information leakage can have serious consequences in communication environments. Organizations relying on pjproject-based VoIP infrastructure, including enterprises, service providers, and government agencies, may face risks of data exposure and privacy violations. The lack of authentication or user interaction requirements increases the attack surface, enabling remote exploitation from unauthenticated attackers. The impact is heightened in environments with high volumes of SIP traffic or sensitive communications.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 20 Mar 2026, 16:08 UTC

WeaknessesCWE-125

Technical details

References

Community reviews

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