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XML::Bare EUVDEUVD-2026-44966

| CVE-2026-57074 CRITICAL
Out-of-bounds Read (CWE-125)
2026-07-16 CPANSec GHSA-xm8x-vw7j-573w
Critical
Disputed · 9.1 Vendor: CPANSec
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Reach XML parsing endpoint
  2. Delivery
    Send truncated XML ('<a/')
  3. Exploit
    Trigger unbounded lookahead in parserc_parse
  4. Execution
    Read past buffer boundary
  5. Impact
    Crash worker or leak adjacent memory

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, read limits
MITRE ATT&CK

1 technique across 1 tactic: Collection

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Exploitation requires only that the target application pass attacker-controlled XML input to XML::Bare's parser (parserc_parse) in a version at or below 0.53 - the concrete trigger is a truncated or improperly terminated construct, such as an element tail like '<a/' lacking the closing '>' or a partial '<![CDATA[' token, that ends near the buffer boundary so the multi-byte lookahead reads past it. The CVSS vector (AV:N/AC:L/PR:N/UI:N) indicates no authentication and no user interaction against a network-reachable parser. The principal LIMITING factor is deployment: the flaw is only reachable to the extent the application actually parses untrusted or remote XML with this specific module - a program that only parses trusted local XML reduces this to a local (AV:L) issue, and impact is bounded (likely a crash or small adjacent-memory read rather than full data exfiltration), consistent with SSVC's 'partial' technical impact.

Impact

Signals conflict on severity. The published CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N/C:H/I:N/A:H, score 9.1) treats this as a high-confidentiality, high-availability network flaw, but SSVC rates Technical Impact only 'partial' and Exploitation 'none', and EPSS is low at 0.19% (8th percentile). The realistic impact of a bounded lookahead OOB read is a process crash (denial of service) or leakage of a few bytes of adjacent memory - the 'C:H' rating in particular looks generous for a small over-read, which is why the independent assessment below downgrades confidentiality and availability to Low. What raises priority is exposure and automatability: any Perl service that parses attacker-supplied XML with XML::Bare is reachable network-side with no authentication or user interaction, and SSVC marks it automatable=yes, so opportunistic fuzzing-style triggering is plausible. Net: not an emergency (no KEV, no known exploit, low EPSS) but a genuine reliability/DoS concern worth patching promptly where untrusted XML is processed. The 'network' attack vector is context-dependent - it applies only when the XML originates from a remote source; a tool parsing only local files would effectively be local (AV:L).

Exploit ScenarioDerived

An attacker sends a crafted, truncated XML payload (for example a document ending in '<a/' with no closing '>') to a Perl web service or job that parses request bodies with XML::Bare. The unbounded lookahead in parserc_parse dereferences bytes past the buffer, crashing the worker (denial of service) or returning a few bytes of adjacent heap memory. No authentication or user interaction is required; no public exploit is identified, but the trigger is trivial to construct and automatable per SSVC.

Act Now Prioritize within 24-48h. Why: CRITICAL severity.
Patch available 0.2% exploitation probability (EPSS)

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AnalysisAIv1 – Jul 17, 2026

Out-of-bounds read in the XML::Bare Perl XML parser (all releases through 0.53) lets a remote attacker crash the parsing process or disclose small amounts of adjacent process memory by feeding it a truncated or malformed XML document. The parserc_parse C routine performs multi-character lookahead (for tokens like '<![CDATA[' and element terminators) without verifying the offsets stay inside the input buffer, so inputs such as '<a/' read past the end. There is no public exploit identified at time of analysis and EPSS is low (0.19%), but SSVC rates the flaw automatable, reflecting how easily malformed XML can be delivered to any service that parses untrusted input with this module.

RemediationAI

Upstream fix available (PR/commit); released patched version not independently confirmed - no exact fixed release number is present in the provided data. Apply the CPANSec-published patch at https://security.metacpan.org/patches/X/XML-Bare/0.53/CVE-2026-57074-r1.patch, or pull the upstream change in https://github.com/nanoscopic/perl-XML-Bare/pull/1, which adds bounds checks: requiring the full '<![CDATA[' sequence (checking cpos+8 == '[') before advancing, and advancing past an assumed '>' only when the next byte is non-NUL (if(*(cpos+1)) cpos+=2; else cpos++) so a truncated tail cannot skip past the terminator. Rebuild the XS/C module after patching. Where you cannot patch immediately, reduce exposure by not feeding untrusted or externally sourced XML to XML::Bare - validate and size-check input and reject truncated or malformed documents upstream, or route untrusted XML through a hardened parser such as libxml2-based XML::LibXML instead; the trade-off is added dependency weight and possible behavioral or API differences from XML::Bare's lenient parsing. Monitor CPAN for a tagged release that incorporates this patch and upgrade to it once published.

Affected VersionsENISA

XML::Bare 0 ≤0.53

Affected Packages

euvd xml_bare no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

XML::Bare is a lightweight CPAN XML parser for Perl whose performance-critical parsing is implemented in C (parser.c). The vulnerable parserc_parse function walks the input with a cursor (cpos) and peeks ahead several bytes to recognize constructs - for example it tests cpos+7 for the 'A' in '<![CDATA[' and elsewhere assumes the byte after a token is '>' before advancing cpos+=2. Because these dereferences and pointer advances are not bounds-checked against the NUL terminator or buffer length, a truncated tail such as '<a/' causes reads (and cursor advancement) past the allocated buffer. This is a classic CWE-125 out-of-bounds read: the root cause is trusting structural assumptions about well-formed XML rather than validating each offset before dereferencing. The affected component is identified by CPE cpe:2.3:a:codechild:xml::bare (CPAN distribution XML-Bare).

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Severity by source

Sources disagree (Medium–Critical)
Vendor (CPANSec) PRIMARY 9.1 CRITICAL
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
vuln.today AI 6.5 MEDIUM

Unauthenticated malformed-XML input (PR:N/UI:N/AC:L); network vector holds only when XML is remote; bounded lookahead over-read yields limited disclosure and crash, so C:L/A:L, I:N.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
SUSE 6.1 MEDIUM
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L

vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.

CVSS VectorVendor: CPANSec

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High

Lifecycle Timeline

3
CVSS changed
Jul 17, 2026 - 19:22 NVD
9.1 (CRITICAL)
CVE Published
Jul 16, 2026 - 16:15 cve.org
UNKNOWN (no severity yet)
CVE Published
Jul 16, 2026 - 16:15 cve.org
CRITICAL 9.1

DescriptionCVE.org

XML::Bare versions through 0.53 for Perl have an unbounded character lookahead.

The parserc_parse function attempts to check for multicharacter strings such as "<![CDATA" or element terminators such as ">" without checking that the offsets are within the buffer.

Truncated strings such as "<a/" can trigger an out-of-bounds read.

Executive ViewAI

Why It Matters

XML::Bare, a widely-used Perl XML parsing library, contains a critical remote vulnerability (CVSS 9.1) that allows attackers to crash services or extract adjacent process memory through malformed XML documents. Any organization using this library to parse untrusted input faces immediate risk of service disruptions and potential exposure of sensitive data from application memory. Immediate patch deployment is essential given the ease of exploitation and organizational dependency on this module.

Business Impact: Severe
Compensating Controls

Apply vendor patch.

Threat Intelligence Overview

EPSS Score
0.2%
Top 92% exploitable
Prevalence
Low
niche Perl CPAN XML parser, limited enterprise footprint
Social Media
1
Sightings
Data Quality
8 sources
Confidence: High
EUVD NVD CVE.org EPSS Vulnrichment Vendor CIRCL GitHub VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity CRITICAL
CISA KEV No
Public POC No
EPSS 0.2%
Patch available Yes
Active threat No
Deciding rule
CRITICAL severity
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Out-of-Cycle
Exploitation
None
System Exposure· derived
Open
Automatable
Yes
Human Impact
Very High
Technical Impact
Partial

Priority Score

46
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +46
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
openSUSE Leap 16.0 Fixed
openSUSE Tumbleweed Fixed
SUSE Linux Enterprise Module for Development Tools 15 SP7 Affected
SUSE Linux Enterprise Server 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected

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