CVE-2026-40614

PJSIP: Heap buffer overflow in Opus codec decoding

Published Apr 21, 2026 CVSS 4.0 · 8.5 High EPSS < 1% KEV · Not listed

Description

PJSIP is a free and open source multimedia communication library written in C. In 2.16 and earlier, there is a buffer overflow when decoding Opus audio frames due to insufficient buffer size validation in the Opus codec decode path. The FEC decode buffers (dec_frame[].buf) were allocated based on a PCM-derived formula: (sample_rate/1000) * 60 * channel_cnt * 2. At 8 kHz mono this yields only 960 bytes, but codec_parse() can output encoded frames up to MAX_ENCODED_PACKET_SIZE (1280) bytes via opus_repacketizer_out_range(). The three pj_memcpy() calls in codec_decode() copied input->size bytes without bounds checking, causing a heap buffer overflow.

Analysis

Technical impact

PJSIP versions 2.16 and earlier contain a heap buffer overflow in the Opus codec decode path caused by insufficient buffer size validation when allocating FEC decode buffers. The three memcpy calls copy the full input frame size without checking bounds, so a maliciously sized frame can overwrite adjacent heap memory. The flaw is a classic CWE‑122 situation that can allow an attacker to execute arbitrary code or crash the application.

Affected Systems

The affected product is the PJSIP multimedia library (pjproject) released before version 2.17. Any deployment that uses pjsip 2.16 or earlier for Opus audio decoding is vulnerable. No additional vendor or product details are provided beyond the pjproject identifier.

Risk and Exploitability

The CVSS score of 8.5 indicates a high severity flaw with significant impact. EPSS data is not available, so the exploitation likelihood is uncertain, but the vulnerability is not listed in CISA KEV. The likely attack vector is through network traffic, as an attacker can send crafted Opus frames to any service using the vulnerable decoder, potentially leading to arbitrary code execution. The absence of a mitigation in the advisory suggests that deploying the fixed version is critical for reducing risk.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

pjsip

pjproject

affected

Version	Status	Constraints
`<= 2.16`	affected	—

Configuration 1 [-]

cpe:2.3:a:pjsip:pjsip:*:*:*:*:*:*:*:*

No data.

Vendor Product Versions

Pjsip

Pjproject

Version	Status	Scheme	Platform
`[0,2.16]`	affected	generic	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Apply the latest release of pjproject (2.17 or newer) where the buffer size validation fix has been applied.
If an immediate upgrade is not possible, isolate the affected service from untrusted networks or reject Opus frames larger than 960 bytes to reduce the risk of a buffer overflow.
Conduct a security audit of the media server to ensure that no other similar overflows exist and that all codec configurations enforce proper bounds checking.

Generated by OpenCVE AI on April 22, 2026 at 05:36 UTC.

Tracking

Advisories

Source	ID	Title
Debian DLA	DLA-4631-1	asterisk security update

Metrics

Attack Vector Local

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction Passive

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.224% probability within 30 days)

Exploitation none

Automatable no

Technical Impact total

References

Link	Providers
https://github.com/pjsip/pjproject/commit/17897e835818f8ee03b1806ddcd7b95ea16d2c0e
https://github.com/pjsip/pjproject/security/advisories/GHSA-j59p-4xrr-fp8g

History

Apr 23, 2026 4:15 PM First appearance in the feed. Affected versions updated. Affected vendors updated. Scoring metrics updated View changes

Type	Values Removed	Values Added
First Time appeared		Pjsip pjsip
CPEs		cpe:2.3:a:pjsip:pjsip::::::::
Vendors & Products		Pjsip pjsip
Metrics		cvssV3_1 `{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}`

Apr 22, 2026 2:15 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

Apr 22, 2026 3:45 AM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Pjsip Pjsip pjproject
Vendors & Products		Pjsip Pjsip pjproject

Apr 22, 2026 12:00 AM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		PJSIP is a free and open source multimedia communication library written in C. In 2.16 and earlier, there is a buffer overflow when decoding Opus audio frames due to insufficient buffer size validation in the Opus codec decode path. The FEC decode buffers (dec_frame[].buf) were allocated based on a PCM-derived formula: (sample_rate/1000) * 60 * channel_cnt * 2. At 8 kHz mono this yields only 960 bytes, but codec_parse() can output encoded frames up to MAX_ENCODED_PACKET_SIZE (1280) bytes via opus_repacketizer_out_range(). The three pj_memcpy() calls in codec_decode() copied input->size bytes without bounds checking, causing a heap buffer overflow.
Title		PJSIP: Heap buffer overflow in Opus codec decoding
Weaknesses		CWE-122
References		https://github.com/pjsip/pjproject/commit/17897e835818f8ee03b1806ddcd7b95ea16d2c0e https://github.com/pjsip/pjproject/security/advisories/GHSA-j59p-4xrr-fp8g
Metrics		cvssV4_0 `{'score': 8.5, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}`