---
title: "OpenAI Fixed image encoding bug affecting visual understanding: 2026-09-25 | Harbyn"
description: "OpenAI Fixed image encoding bug affecting visual understanding, announced Sep 25, 2026."
canonical: "https://harbyn.com/changes/openai/2026-09-25-fixed-image-encoding-bug-affecting-visual-understanding"
last-updated: 2026-09-26
---

# OpenAI Fixed image encoding bug affecting visual understanding

Markdown version of <https://harbyn.com/changes/openai/2026-09-25-fixed-image-encoding-bug-affecting-visual-understanding>.

Behavior change - OpenAI. low severity. Announced.

A bug in image encoding that degraded image understanding in GPT-6 Sol and GPT-6 Luna was fixed, improving results on visual tasks in the API and Codex, including computer use. OpenAI recommends rerunning evaluations and retrying workflows with image inputs affected by the issue.

## Facts

| Fact | Value |
| --- | --- |
| Vendor | [OpenAI](https://harbyn.com/vendors/openai.md) |
| Kind | Behavior change |
| Severity | low |
| Status | Announced |
| Announced | Sep 25, 2026 |
| Added to Harbyn | Sep 26, 2026 |
| Lead time | No dated deadline |
| Model IDs | `gpt-6-sol`, `gpt-6-luna` |
| Review | Reviewed by a person, extracted by a model |

## Find it in your code

```sh
npx harbyn scan
```

The scanner reads your repository on your machine and reports every file and line that uses the identifiers above. Nothing leaves your machine.

## Sources

Where this event comes from: the page we read, when we read it, and the hash of that snapshot.

- <https://developers.openai.com/api/docs/changelog> (changelog, fetched 2026-09-26 21:15 UTC, sha256 `8f84daf9868aabee497df03eff6efdd0fcd4e538a6cdb4802b4b43f69717a2b2`)

## Related changes

### More from OpenAI

- [Updated chat-latest snapshot](https://harbyn.com/changes/openai/2026-10-07-updated-chat-latest-snapshot.md) (Behavior change, announced Oct 7, 2026)
- [GPT-5.4-Cyber - shutdown 2026-10-01](https://harbyn.com/changes/openai/2026-09-11-gpt-5-4-cyber-shutdown.md) (Retirement, effective Oct 1, 2026)
- [Transcription models - shutdown 2027-02-26](https://harbyn.com/changes/openai/2026-08-26-transcription-models-shutdown.md) (Retirement, effective Feb 26, 2027)
- [Legacy audio, realtime, and transcription models - shutdown 2027-01-20](https://harbyn.com/changes/openai/2026-07-20-legacy-audio-realtime-and-transcription-models-shutdown.md) (Retirement, effective Jan 20, 2027)

### Changes at other vendors

- [Amazon Selling Partner API: ORDER\_CHANGE notifications add PreFulfillmentStatusChange for Amazon Autos](https://harbyn.com/changes/amazon-sp-api/2026-10-14-sp-api-updates-new-listings-items-api-ivp-values-in-eu5-jp-and-ca-stores-oct-3.md) (effective Oct 28, 2026)
- [BigCommerce: 301 redirects will apply only to storefront channels](https://harbyn.com/changes/bigcommerce/2026-10-07-301-redirects-now-apply-to-storefront-channels-only.md) (effective Nov 10, 2026)
- [GitHub: Secret scanning audit log business field changes to enterprise slug](https://harbyn.com/changes/github/2026-10-20-updates-to-github-secret-scanning-7.md) (effective Nov 12, 2026)
- [Jira / Atlassian Cloud: New IP address ranges in use from January 1, 2027](https://harbyn.com/changes/atlassian-jira/2026-10-16-atlassian-cloud-adds-new-ip-address-ranges.md) (effective Jan 1, 2027)

[All upcoming deadlines](https://harbyn.com/deadlines.md)