CVE-2026-6878 ByteDance verl grader.py math_equal sandbox
Remote attackers can exploit a sandbox issue in the math_equal function to execute arbitrary code within the ByteDance verl library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-6878?
CVE-2026-6878 is a medium-severity code injection vulnerability in ByteDance verl, published on 23 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability was identified in ByteDance verl up to 0.7.0. Affected is the function math_equal of the file prime_math/grader.py. The manipulation leads to sandbox issue. It is possible to initiate the attack remotely. The complexity of an attack is rather high. The exploitability is told to be difficult. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure but did not respond in any way.
Which versions are affected by CVE-2026-6878?
3 open source packages ship an affected version, including verl.
| Package | Affected | Fixed in |
|---|---|---|
verl PyPI | All versions to 0.7.1 | None |
verl PyPI | All versions to 0.7.1 | None |
verl PyPI | All versions to 0.7.1 | None |
How do I fix CVE-2026-6878?
No fix has been published for CVE-2026-6878 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-6878 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-6878 exists.
Sources
Also known as GHSA-h57c-v2v3-5v3v, PYSEC-2026-3402.