CVE-2026-31827 Alienbin: TTL Index Race Condition allows unauthorized deletion of other users data
An attacker can delete other users' pastes by exploiting a race condition in the TTL index recreation logic during paste submission.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-31827?
CVE-2026-31827 is a high-severity vulnerability in Blue-B Alienbin, published on 10 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Alienbin is an anonymous code and text sharing web service. In 1.0.0 and earlier, the /save endpoint in server.js drops and recreates the MongoDB TTL index on the entire post collection for every new paste submission. When User B submits a paste with a short TTL (e.g., 30 seconds), the TTL index is recreated with expireAfterSeconds: 30 for all documents in the collection. This causes User A's paste (originally set to 7 days) to be deleted after 30 seconds. An attacker can intentionally delete all existing pastes by repeatedly submitting pastes with ttlOption=30s.
Weakness: CWE-362
Which versions are affected by CVE-2026-31827?
How do I fix CVE-2026-31827?
No fix has been published for CVE-2026-31827 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-31827 being exploited?
There is no known exploitation of CVE-2026-31827 in the wild and no public exploit code.