CVE-2022-23901Public exploit

Process crash via unbounded recursive backpropagation

Published Mar 29, 2022 · Updated Aug 3, 2024

Stack exhaustion in re2c 2.2 allows local users to crash the lexer generator by processing a crafted re2c specification. The re2c::backprop function in src/dfa/dead_rules.cc recursively re-enters itself without a safe depth bound until the process stack is exhausted. Reachability requires local invocation of the command-line tool on attacker-controlled input, and the demonstrated consequence is limited to termination of that process.

CVSS severity4.7
Medium
EPSS probability1.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack exhaustion in re2c 2.2 allows local users to crash the lexer generator by processing a crafted re2c specification. The re2c::backprop function in src/dfa/dead_rules.cc recursively re-enters itself without a safe depth bound until the process stack is exhausted. Reachability requires local invocation of the command-line tool on attacker-controlled input, and the demonstrated consequence is limited to termination of that process.

The record

CVE
CVE-2022-23901
Published
Mar 29, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 29, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
4.7SUSECVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
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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