CVE-2026-35458Public exploitNetwork attack vector

Worker hangs via unbounded scope regex backtracking

Published Apr 7, 2026 · Updated Apr 7, 2026

Regular expression denial of service in Gotenberg 8.29.1 and earlier allows remote attackers to hang workers via crafted scope patterns. The Chromium route parser compiles the scope suffix in extraHttpHeaders with dlclark/regexp2 but leaves MatchTimeout at its effectively infinite default, so nested quantifiers backtrack without a bound. Reachability requires access to a Chromium endpoint accepting extraHttpHeaders; exploitation interrupts availability without reading or changing data.

CVSS severity8.7
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Regular expression denial of service in Gotenberg 8.29.1 and earlier allows remote attackers to hang workers via crafted scope patterns. The Chromium route parser compiles the scope suffix in extraHttpHeaders with dlclark/regexp2 but leaves MatchTimeout at its effectively infinite default, so nested quantifiers backtrack without a bound. Reachability requires access to a Chromium endpoint accepting extraHttpHeaders; exploitation interrupts availability without reading or changing data.

The record

CVE
CVE-2026-35458
Published
Apr 7, 2026
Updated
Apr 7, 2026
Vendor
Gotenberg
Product
Gotenberg
Classifications
CWE-1333, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 7, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 8.29.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Gotenberg · Gotenbergversion=<= 8.29.1

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.7GitHub, Inc.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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1333Inefficient Regular Expression Complexity
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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