Potential third critical PHP CVE

Got really triggered... By the font.

PHP is having a really bad day today

Oh, it's going to be one of those weeks.

From the little info one can see here, it looks like this is a PHP script causing a memory corruption. So you probably need to be able to run PHP code to exploit it. That's... not a particularly unusual issue. PHP has a large codebase, releases with plenty of fixed crashes come out regularly. It becomes critical if there's a remote path to exploitation. I see no indication that this is a "critical" PHP flaw. And the Reply from the person who found it seems to confirm that. ("I keep getting asked about mitigations, here's the mitigation: don't worry about it kitten")

https://www.openwall.com/lists/oss-security/2026/10/21/23

I mean it the first time [0], PHP is done. [0] https://news.ycombinator.com/item?id=50181423

• chinathrow · 57 minutes ago

  It's absolutely not.

There is literally no info on how this is triggered. From the info this could range anywhere from total non issue to zOMG. Given how keyed up everyone is, i lean towards the former. honestly, i would just wait for php announcement and assume its no big deal until then.

That post appears to show the same stack trace as this reported issue https://github.com/php/php-src/issues/24488 , which is a confirmed GC regression in 8.5.12 but it is not exploitable (the allocator's shadow protection kills it), and it does not result in RCE and is not a critical CVE. It's a very different shape to the other two CVEs, and a use-after-free doesn't necessarily immediately imply a critical CVE.

• athrowaway3z · 38 minutes ago

  Stop posting this theory because it's obviously wrong. From the thread: > Elise: confirmed working on 8.5.10 too

  • nr378 · 32 minutes ago

    Whether it's exactly the same issue or not, the point remains: a double-free in and of itself doesn't establish a critical CVE (or even a high one). There's a known double-free in that GitHub issue, if there's a second independent one, it shouldn't necessarily cause any more concern than the first one.

I've spent some deepseek tokens on trying to reproduce this CVE with what is known so far; (Very little beyond effected versions and a hint that her search started because of the current bug, but that it's probably a different one entirely). It found nothing. Take that for what it is. Together with https://www.openwall.com/lists/oss-security/2026/10/21/23 you're probably not going to need to stay up for this.

Source thread: https://fedi.katze.sh/@elise/117479383739450605 ( https://news.ycombinator.com/item?id=50182930 )