# CVE-2026-77396: PJSIP: Heap buffer overflow in the AVI parser

> A heap buffer overflow in the PJSIP AVI parser allows attackers to execute code or crash applications via crafted AVI files.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 18 Sep 2026
- **Updated:** 21 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-77396, GHSA-6p2p-5wf8-h5hr, UBUNTU-CVE-2026-77396

## What is CVE-2026-77396?

CVE-2026-77396 is a medium-severity memory corruption vulnerability in pjsip pjproject, published on 18 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

PJSIP is a free and open source multimedia communication library written in C. In 2.17 and earlier, the PJSIP AVI parser in pjmedia/src/pjmedia/avi_player.c uses an input-file video chunk length as the number of bytes copied into a frame buffer whose capacity is derived from the declared media dimensions. A crafted AVI file can therefore cause an attacker-controlled out-of-bounds write past the heap allocation when an application plays the file or pulls its frames. The existing size assertion does not protect production release builds, where assertions are disabled. Typical local playback can crash the process, while applications that accept untrusted AVI sources expose a stronger memory-corruption condition. No fixed version is available as of this review.

Weakness: CWE-787 (Out-of-bounds Write), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-77396?

It affects 1 product.


Products: Teluu Pjsip.

## How do I fix CVE-2026-77396?

No fix has been published for CVE-2026-77396 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-77396 being exploited?

There is no known exploitation of CVE-2026-77396 in the wild and no public exploit code.

## Other vulnerabilities in pjsip pjproject

- [CVE-2023-38703](https://insights.sbomify.com/CVE-2023-38703/): PJSIP has use-after-free vulnerability in SRTP media transport (critical 9.8)
- [CVE-2022-39269](https://insights.sbomify.com/CVE-2022-39269/): Media transport downgrade from the secure version (SRTP) to non-secure (RTP) in pjsip (critical 9.1)
- [CVE-2026-57161](https://insights.sbomify.com/CVE-2026-57161/): PJSIP: Stack overflow handling Service-Route headers in a registration response (high 8.8)
- [CVE-2026-57162](https://insights.sbomify.com/CVE-2026-57162/): PJSIP: Stack overflow parsing SDP a=crypto attributes (high 8.8)
- [CVE-2026-57163](https://insights.sbomify.com/CVE-2026-57163/): PJSIP: Stack overflow parsing a TLS peer certificate's SubjectAltName in GnuTLS backend (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-77396 and fix it if it is affected.

What it is: CVE-2026-77396 is a medium-severity memory corruption vulnerability in pjsip pjproject, published on 18 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-77396 in the wild and no public exploit code.

Affected product: pjsip pjproject. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-77396/ (Markdown: https://insights.sbomify.com/CVE-2026-77396/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-77396
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-77396
- OSV: https://osv.dev/vulnerability/CVE-2026-77396

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-77396/
Summaries are generated and may contain mistakes; the official description above is the record.