Hi Olly, On Sun, Aug 16, 2026 at 09:57:33AM +1200, Olly Betts wrote: > Package: libxapian30 > Version: 1.4.31-2 > Fixed: 1.4.32-1 > Severity: serious > Tags: security > Justification: potential security vulnerability > X-Debbugs-Cc: Debian Security Team <[email protected]> > > This was reported to upstream's public development list: > > https://lists.xapian.org/pipermail/xapian-devel/2026-August/003429.html > > The bug is missing HTML escaping, potentially allowing an attacker to inject > unescaped data into generated HTML search results. It's effectively a > corner case missed when we fixed CVE-2018-0499. > > It affects upstream releases 1.4.x for x <= 31 and 2.0.0. > Upstream releases 1.4.32 and 2.0.1 include a fix, and I've already > uploaded 1.4.32 to unstable and 2.0.1 to experimental. > > There are patches here: > > https://trac.xapian.org/wiki/SecurityFixes/2018-07-02#a2026-08-13update > The actually fix is just this (the patches also add test coverage): > > > if (hi_start.empty() && hi_end.empty() && text.size() <= length) { > > - // Too easy! > - return text; > + // The text is already short enough so we just need to perform > + // escaping. > + string output; > + append_escaping_xml(text.data(), text.data() + text.size(), output); > + return output; > } > > The 4 variables in the condition are all parameters from the > MSet::snippet() API call. In order to be exploited, hi_start and hi_end > need to be passed as empty strings (they have default values which > aren't empty). I'd expect most usage in a web context would want to > highlight matching terms in the snippet and so it's probably uncommon to > pass empty string here - I looked for an example of such usage with > codesearch.d.n but didn't find anything. > > However empty highlighting strings are a legitimate way to call this > method, and I may have missed an instance, or such use may be present in > code that hasn't been packaged for Debian. Therefore I think we should > apply this patch to stable. > > I've already contacted the security team and they said we should handle > this via a stable update.
FTR, I requested a CVE for this issue so we can properly track it as separate CVE id. Regards, Salvatore
