CVE-2026-77806: SPIP before 4.4.21 allows unauthenticated remote attackers to execute arbitrary code, as exploited in the wild

Q: How do I fix CVE-2026-77806?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Q: Is CVE-2026-77806 being exploited?

CVE-2026-77806 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-77806 affect?

CVE-2026-77806 affects affected software. Severity is critical (CVSS 9.8). SPIP before 4.4.21 allows unauthenticated remote attackers to execute arbitrary code, as exploited in the wild in August 2026. This is related to code injection via an X-Spip-Filtre HTTP request header that is mishandled by analyse_resultat

Q: How urgent is CVE-2026-77806?

Priority 65/100. Critical severity; EPSS top 9%: very likely to be exploited; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTE

CVE-2026-77806 is a critical-severity flaw (CVSS 9.8) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

SPIP before 4.4.21 allows unauthenticated remote attackers to execute arbitrary code, as exploited in the wild in August 2026. This is related to code injection via an X-Spip-Filtre HTTP request header that is mishandled by analyse_resultat_skel.

Why this priority

Critical severity
EPSS top 9%: very likely to be exploited
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	4.5% (top 9%)
CISA exploited list	No
Weakness	CWE-94
Published	2026-08-21
Last modified	2026-10-15

Publisher (CNA): MITRE

Last updated 2026-10-15 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-08-21 14:16 UTCPublished CVE record published
2026-10-15 19:10 UTCUpdated Record last modified

Exact fixes by distribution

Debian 13 · spip · FIXED · 4.4.21+dfsg-0+deb13u1

sudo apt update && sudo apt install --only-upgrade spip dpkg --compare-versions "$(dpkg-query -W -f='${Version}' spip)" ge "4.4.21+dfsg-0+deb13u1" && echo PATCHED || echo STILL-VULNERABLE

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: CuteeCat/CVE-2026-77806 (2 stars)
Nuclei scan template: SPIP < 4.4.22 - Unauthenticated RCE

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-77806?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-77806 being exploited?

CVE-2026-77806 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-77806 affect?

CVE-2026-77806 affects affected software. Severity is critical (CVSS 9.8). SPIP before 4.4.21 allows unauthenticated remote attackers to execute arbitrary code, as exploited in the wild in August 2026. This is related to code injection via an X-Spip-Filtre HTTP request header that is mishandled by analyse_resultat

How urgent is CVE-2026-77806?

Priority 65/100. Critical severity; EPSS top 9%: very likely to be exploited; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

References

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