6.9

CVE-2026-83611: xmldom: Parser silently accepts a not-well-formed end tag whose name is followed by a line break and trailing content

Deferred
AliasesUBUNTU-CVE-2026-83611DEBIAN-CVE-2026-83611GHSA-6h8r-xr42-gp59
Published 01-09-2026Last modified 01-09-2026

Vulnerability summary

CVE-2026-83611 is a medium (CVSS 6.9) vulnerability in xmldom. EPSS estimates a 0.62% chance of exploitation in the next 30 days, higher than 49.7% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.9, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.9/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.62%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 01-09-2026
    PublishedVulnerability first disclosed.
  2. 01-09-2026
    Last modifiedVulnerability information updated.

Description

xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. Prior to @xmldom/xmldom versions 0.8.15 and 0.9.12, and in xmldom version 0.6.0 and earlier, DOMParser.parseFromString() can silently accept an end tag such as </a\njunk>, close the element, and discard the trailing content. On 0.9.x, the lib/sax.js end-tag validator inherits the multiline flag from reg(), allowing the first line to satisfy the anchored XML ETag production; older lines have no equivalent residue validation. This parser differential can bypass a parse-before-trust well-formedness gate, although it does not inject the discarded content; onError on 0.9.x and errorHandler on 0.8.x are the relevant reporting interfaces. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.

CVSS metrics

6 scores · 6 sources · 1 version

EPSS trend

Probability

0.62%

Chance of exploitation in the next 30 days

Percentile

50%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.62% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard3 products
  • gitlab-rails-ce-18.11< 18.11.11-r2
  • gitlab-rails-ce-19.0All versions (No fix recorded) | < 19.0.10-r0
  • gitlab-rails-ce-fips-19.0< 19.0.9-r3
@xmldom1 product
  • xmldom≥ 0.7.0, < 0.8.15 | ≥ 0.9.0, < 0.9.12
Debian1 product
  • node-xmldomAll versions (No fix recorded) | < 0.9.12-1
Npm1 product
  • xmldom≤ 0.6.0
Ubuntu1 product
  • node-xmldomAll versions (No fix recorded)
Xmldom1 product
  • xmldom≤ 0.6.0 | ≥ 0.9.0, < 0.9.12 | ≥ 0.7.0, < 0.8.15

6 vendors · 8 products

References

13 links
Show all 13 references