DEBIAN-CVE-2026-54905
concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReentrantReadWriteLock can incorrectly grant a write lock after one thread acquires the read lock 32,768 times. The lock stores a thread's local read and write hold counts in one integer. The low 15 bits are used for the read hold count, and bit 15 is used as WRITE_LOCK_HELD. After 32,768 reentrant read acquisitions, the local read count crosses into the write-lock bit. try_write_lock then treats the thread as already holding a write lock and returns true without setting the global RUNNING_WRITER bit. This breaks the core mutual-exclusion guarantee: the caller is told it has a write lock, but other threads can still hold or acquire read locks at the same time. This vulnerability is fixed in 1.3.7.
DEBIAN-CVE-2026-54905
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-54905
ruby-concurrent
Source reference: /affected/0/package/name
- Affected versions
- 1.1.6+dfsg-5
Source reference:
/affected/0/versions1.2.3-1Source reference:
/affected/0/versions1.2.3-2Source reference:
/affected/0/versions1.2.3-3Source reference:
/affected/0/versions1.2.3-4Source reference:
/affected/0/versions1.3.4-1Source reference:
/affected/0/versions1.3.4-1~exp1Source reference:
/affected/0/versions1.3.5-1Source reference:
/affected/0/versions1.3.6-1Source reference:
/affected/0/versions1.3.7-1Source reference:
/affected/0/versions1.3.7-2Source reference:
/affected/0/versions1.3.7-3Source reference:
/affected/0/versions1.3.7-4Source reference:
/affected/0/versions1.3.8-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
ruby-concurrent
Source reference: /affected/1/package/name
- Affected versions
- 1.3.5-1
Source reference:
/affected/1/versions1.3.6-1Source reference:
/affected/1/versions1.3.7-1Source reference:
/affected/1/versions1.3.7-2Source reference:
/affected/1/versions1.3.7-3Source reference:
/affected/1/versions1.3.7-4Source reference:
/affected/1/versions1.3.8-1Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
ruby-concurrent
Source reference: /affected/2/package/name
- Affected versions
- 1.3.5-1
Source reference:
/affected/2/versions1.3.6-1Source reference:
/affected/2/versions - Fixed versions
- 1.3.7-1
Source reference:
/affected/2/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ruby-concurrent",
"purl": "pkg:deb/debian/ruby-concurrent?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"1.1.6+dfsg-5",
"1.2.3-1",
"1.2.3-2",
"1.2.3-3",
"1.2.3-4",
"1.3.4-1",
"1.3.4-1~exp1",
"1.3.5-1",
"1.3.6-1",
"1.3.7-1",
"1.3.7-2",
"1.3.7-3",
"1.3.7-4",
"1.3.8-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54905.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ruby-concurrent",
"purl": "pkg:deb/debian/ruby-concurrent?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"1.3.5-1",
"1.3.6-1",
"1.3.7-1",
"1.3.7-2",
"1.3.7-3",
"1.3.7-4",
"1.3.8-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54905.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.3.7-1"
}
]
}
],
"package": {
"name": "ruby-concurrent",
"purl": "pkg:deb/debian/ruby-concurrent?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"1.3.5-1",
"1.3.6-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-54905.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #57842 · Revision 1
- Added to Heist Feed
- Publisher date