Raw 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/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:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-40614 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Pjsip Pjsip. Its CVSS base score is 8.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-40614 is a heap buffer overflow vulnerability (CWE-122) affecting PJSIP, a free and open-source multimedia communication library written in C, in versions 2.16 and earlier. The flaw arises in the Opus codec decode path due to insufficient buffer size validation when decoding Opus audio frames. FEC decode buffers (dec_frame[].buf) are allocated using a PCM-derived formula—(sample_rate/1000) * 60 * channel_cnt * 2—which, for example, provides only 960 bytes at 8 kHz mono. However, codec_parse() can output encoded frames up to MAX_ENCODED_PACKET_SIZE (1280 bytes) via opus_repacketizer_out_range(), and the three pj_memcpy() calls in codec_decode() copy input->size bytes without bounds checking, triggering the overflow.
The vulnerability has a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), indicating exploitation is possible remotely over the network by unauthenticated attackers with low complexity, though it requires user interaction, such as processing a maliciously crafted Opus audio frame in an application using PJSIP. Successful exploitation can lead to high confidentiality, integrity, and availability impacts, potentially enabling arbitrary code execution, data corruption, or denial of service via heap overflow.
Mitigation is detailed in the PJSIP project's GitHub security advisory (GHSA-j59p-4xrr-fp8g) and addressed by commit 17897e835818f8ee03b1806ddcd7b95ea16d2c0e, which fixes the buffer allocation and validation issues. Affected users should update to a PJSIP version incorporating this patch and review applications for proper handling of Opus audio decoding.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-24229
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.4.1
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (including fuzzing and memory-error detectors) can discover heap overflows after they have been coded.
Input validation enforces bounds checking on data written to heap buffers, directly stopping the overflow condition from being introduced.
Security engineering principles require use of memory-safe constructs and bounds-checked allocation routines that avoid introducing heap overflows.
Memory-protection mechanisms limit the ability of a heap overflow to execute attacker-controlled code or corrupt adjacent structures.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Vulnerability scanning and recording can discover heap-overflow flaws but does not prevent their introduction in code.
Timely patching removes known heap-overflow instances after they exist.
Secure-development practices directly require bounds checking and safe memory handling that prevent heap overflows.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure development lifecycle mandates practices that reduce the likelihood of introducing heap overflows.
Application security requirements can specify bounds-checking and safe memory APIs that mitigate heap overflows.
Secure architecture and engineering principles include memory-safety and input-validation controls that address heap overflows.
Secure coding standards directly prescribe techniques (safe functions, bounds checks) that prevent heap-based buffer overflows.
Security testing in development and acceptance can detect heap overflows before release.