NVD / CVE Program· CNA Google

CVE-2026-87721: Denial of Service via Exponential Backtracking in ANTLR Search Query Parser in Gerrit Code Review

HighCVSS 8.7 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 34/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.32% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: Gerrit Gerrit 3.12.10, 3.13.9, 3.14.3.

Low priority for now. Upgrade to Gerrit Gerrit 3.12.10, 3.13.9, 3.14.3 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Uncontrolled Resource Consumption (CWE-400 / CWE-407) in the ANTLR 3 search query parser (QueryParser / Query.g) in Gerrit Code Review versions 2.0.19 through 3.12.9, 3.13.0 through 3.13.8, and 3.14.0 through 3.14.2 allows an unauthenticated remote attacker (or an authenticated user if anonymous read access is disabled) to cause a persistent denial of service (CPU exhaustion and HTTP worker thread pool starvation requiring a server restart) via crafted search queries containing deeply nested parentheses sent to query evaluation endpoints (/changes/?q=, /accounts/?q=, /groups/?query=, /projects/?query=, /Documentation/?q=, /changes/{id}/query?expression=, or SSH gerrit query). Because syntactic predicates in conditionOr and conditionAnd recurse via conditionBase without memoization prior to capability or visibility checks and worker threads do not abort when the client disconnects, a small number of requests (such as 25 requests matching default httpd.maxThreads) can permanently pin all HTTP worker threads. This issue is fixed in Gerrit Code Review versions 3.12.10, 3.13.9, and 3.14.3.

EUVD-2026-86477

Published: Sep 24, 2026
Updated: Sep 25, 2026
EPSS: 0.3% · 25th percentile
CWE: CWE-400

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 34 / 40 · 8.7 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.3%

CISA SSVC decision

Exploitation: proof of concept
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Google: 8.7; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (Google). Independent of NVD's CPE analysis and usually ahead of it.

Gerrit Gerrit
- 2.0.19 and later · before 3.12.10affected · semver
- 3.13.0 and later · before 3.13.9affected · semver
- 3.14.0 and later · before 3.14.3affected · semver

Same product

gerrit: all records

Other highest-scoring records for the same primary product.

CVE-2026-87722Regular Expression Denial of Service (ReDoS) in Search Query Predicates and REST Filter Endpoints in Gerrit Code Review
34Monitor
CVE-2026-87720Incorrect Authorization via Stale ProjectCache Eviction and Repeated .git Suffixes in Gerrit Code Review
30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Gerrit Gerrit	3.12.10	Vendor (CNA)
Gerrit Gerrit	3.13.9	Vendor (CNA)
Gerrit Gerrit	3.14.3	Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Amin Alemifinder

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-877220 days apartRegular Expression Denial of Service (ReDoS) in Search Query Predicates and REST Filter Endpoints in Gerrit Code Review
34Monitor

Not on record for this CVE: patch commit or PR link · public bounty program.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: X

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Endpoint Denial of ServiceT1499

Change log (1)

Fix✗ → ✓Sep 28, 2026, 10:09 PM UTC

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References

issues.gerritcodereview.com/issues/541287630

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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