CVE-2026-58502
An issue title containing shell command-substitution syntax can therefore execute commands on the GitHub Actions runner before the title is included in the Discord notification sent through DISCORD_WEBHOOK.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.53%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
githubtoplanguages generates a user's top GitHub languages as an SVG. The .github/workflows/discord-issue.yml workflow runs when an issue is opened or closed and interpolates github.event.issue.title directly into the Bash assignment for ISSUE_TITLE before shell parsing. An issue title containing shell command-substitution syntax can therefore execute commands on the GitHub Actions runner before the title is included in the Discord notification sent through DISCORD_WEBHOOK. Successful exploitation can manipulate or spoof trusted bot notifications and may expose the Discord webhook secret or other workflow environment data, depending on repository permissions. This issue is fixed by commit 6bf9c3a9cb66c937b9047ca266b3d02f2bb11027.
- CVSS 4.0
- 7.1 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/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/M
- EPSS
- 0.53% probability · 45th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-78
- Source
- security-advisories@github.com
EPSS 0.5% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.