The archive/CVE-2022-25883
npm/node-semverDisclosed 2022

CVE-2022-25883:node-semver: Regular-expression denial of service

A reconstruction of the flaw, and the evidence path Lachesis follows to make it visible.

Historical recordv7.5.1 (affected: <7.5.2, <6.3.1, <5.7.2)
WeaknessCWE-1333 · Regular-expression denial of service
ImpactA regular-expression denial of service in node-semver, reachable from attacker-controlled input.
Read the reconstruction
01What happened

An attacker-supplied semver range/version string with a long crafted whitespace/coefficient run.

That is the shape of the failure. The rest of this case file follows the evidence behind it.

Separate the record from the run

What was known.
What Lachesis established.

01Historical record

Known before Lachesis ran

The CVE and vulnerable release were selected from public history. We are not claiming novel discovery.

CVE
CVE-2022-25883
Vulnerable target
v7.5.1 (affected: <7.5.2, <6.3.1, <5.7.2) · vulnerable
Prior knowledge
CVE-2022-25883 · v7.5.1 (affected: <7.5.2, <6.3.1, <5.7.2) is vulnerable
then
02Lachesis run
Verified captured run

Independent re-detection

The experiment graph was built around the vulnerable release, enriched (pass2 dataflow + atropos bind + pass3 semantic), then enumerated BLIND over the whole constructor registry (no family hard-coded, no target line seeded). The lead below is the class-matched candidate the enumerator surfaced on its own; the provenance and body reads are the tool's own follow-up operations. Prose in `adjudication`/`trace` is MY reading of the verbatim source + official fix, clearly separated from tool output.

Seeded inputs
None
Run timestamp
2026-08-29T00:00:00Z
Evidence artifact
cve-2022-25883.kuzu (built from the vulnerable release, enriched pass2+pass3; graph + sidecars deleted after capture)

The commands and outputs below come from this recorded Lachesis run.

The reconstruction, in one frame

What Lachesis reconstructed.

One historical repository. Four captured queries. A complete source-to-sink argument.

Lachesis Casefiles · Unbound ComputeVerified runCVE-2022-25883
An attacker-supplied semver range/version string with a long crafted whitespace/coefficient run.
01Sourcesrc[index] = value
02Sinkre[index] = new RegExp(value, isGlobal ? 'g' : undefined)
03Missing guardnew RegExp(value, isGlobal ? 'g' : undefined)
$ lachesis sources_of → reaches → guard_dominance
npm/node-semver · v7.5.1 (affected: <7.5.2, <6.3.1, <5.7.2) · vulnerableunboundcompute.com
This was known history. Your code is not.

Lachesis follows the same evidence path through unfamiliar repositories.

The Lachesis reconstruction

Here is how the path becomes visible.

These are the recorded questions Lachesis asked of the historical vulnerable code, followed by the raw result and source location each query returned.

Repositorynpm/node-semver
Revisionv7.5.1 (affected: <7.5.2, <6.3.1, <5.7.2) · vulnerable
EngineLachesis

Captured runA real replay of Lachesis over the graph we built for this case. Every `output` below is verbatim captured tool text; the graph was built bounded (hard memory/time cap) and released immediately after capture, so nothing accumulates.

01 · load_graph01 / 05
Lachesis ran
load_graph --path cve-2022-25883.kuzu --profile all && candidate_census

Load the graph and list every bug family

Load the graph built from the vulnerable release and list every bug family the blind enumerator knows -- no family is pre-selected.

Captured resultCaptured · load_graph
raw captured outputload_graph
{"move": "load_graph", "graph": "/Users/riyandhiman/.claude/jobs/12d61190/tmp/hr/cve-2022-25883.kuzu", "profile": "all", "nodes": 70457}
CANDIDATE_CENSUS
move: candidate_census
taxonomy (8):
    domain=lifecycle  title=Resource lifecycle  meaning=an operation that acquires, releases, uses, or transfers a tracked resource  obligation=resource operations stay within the object's lifetime  primary=True  languages=['c', 'python', 'javascript', 'typescript']  enumerable=True  families=[{'family': 'acquire', 'obligation': 'resource acquisition', 'constructor': 'lifecycle.acquire', 'enumerable': True}, {'family': 'release', 'obligation': 'resource release', 'constructor': 'lifecycle.release', 'enumerable': True}, {'family': 'use', 'obligation': 'tracked resource use', 'constructor': 'lifecycle.use', 'enumerable': True}, {'family': 'escape', 'obligation': 'resource ownership transfer', 'constructor': 'lifecycle.escape', 'enumerable': True}, {'family': 'leak', 'obligation': 'Allocated object remains live at an exit', 'constructor'
    ... [truncated]
internal/re.jsline 0
Code location returned for this evidence step.
The repair

A small line with a large consequence.

the createToken choke point compiles token sources verbatim, with no guard that a token's quantifiers are non-overlapping/bounded

Before
new RegExp(value, isGlobal ? 'g' : undefined)
After the patch
// 7.5.2 bounded the quantifiers in the affected token sources
Sources & further reading

The original record.

Read the historical advisory and vulnerability record behind this reconstruction.

Open the Lachesis quickstart