Vulnerability · Published Mar 10, 2026 · Assigned by GitHub_M

CVE-2026-31827Alienbin: TTL Index Race Condition allows unauthorized deletion of other users data

High 7.1

In plain English

A high-severity race condition in Alienbin from Blue-B. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities).

Severity (CVSS 4.0)7.1High

Exploit odds (30 days)0.2%top 89.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
Blue-B	Alienbin	<= 1.0.0

Weakness: CWE-362 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References

https://github.com/Blue-B/Alienbin/security/advisories/GHSA-hqvr-6v89-gwff x_refsource_CONFIRM