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Fencer Vulns
medium 4.4

CVE-2026-77643 json

A cross-site scripting vulnerability in queryparser/termgenerator_internal.cc in Xapian xapian...

published 2026-08-20 2 mo ago modified 2026-10-18 21 d ago also EUVD-2026-63667 , GHSA-955x-jgcw-hcxh , JLSEC-2026-1387

cvss
4.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

A cross-site scripting vulnerability in queryparser/termgenerator_internal.cc in Xapian xapian-core before 2.1.0 and before 1.4.32 exists due to incomplete HTML escaping by Xapian::MSet::snippet(). NOTE: this issue exists because of a missed corner case of CVE-2018-0499.

Patch / fix

  • Xapian xapian-core 1.4.32, 2.1.0
  • xapian-core Debian 13 1.4.29-3+deb13u1
  • xapian-core Debian 14 1.4.32-1

debian advisories DEBIAN-CVE-2026-77643

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-77643 updated cvss 4.4

xapian-core: Xapian xapian-core: Arbitrary code execution via incomplete HTML escaping

  • Red Hat Enterprise Linux 8 xapian-core, xapian-core-libs Red Hat Enterprise Linux 9 xapian-core, xapian-core-libs Red Hat Enterprise Linux 10 xapian-core
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.4 CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N
OSV 3.1 4.4 CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
julia xapian_jll
all versions
 no fix listed

Affected products

  • Xapian xapian-core

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.